From d12a81782e69940b0cb380b5c218f92b911a50cb Mon Sep 17 00:00:00 2001 From: Davis Plumlee <56367316+dplumlee@users.noreply.github.com> Date: Wed, 13 Nov 2024 15:59:15 -0500 Subject: [PATCH] [Security Solution] Fixes multi-line diff algorithm performance in the `upgrade/_review` endpoint (#199388) **Fixes https://github.com/elastic/kibana/issues/199290** ## Summary The current multi-line string algorithm uses a very inefficient regex to split and analyze string fields, and exponentially increases in time complexity when the strings are long. This PR substitutes a much simpler comparison regex for far better efficiency as shown in the table below. ### Performance between different regex options using sample prebuilt rule setup guide string | | `/(\S+\|\s+)/g` (original) | `/(\s+)/g` | `/(\n)/g` | `/(\r\n\|\n\|\r)/g` | |-----------------------|---------------|----------|---------|-------------------| | Unit test speed | `986ms` | `96ms` | `1ms` | `2ms` | | FTR test with 1 rule | `3.0s` | `2.8s` | `2.0s` | `2.0s` | | FTR test with 5 rules | `11.6s` | `6.8s` | `6.1s` | | ### Performance between different regex options using intentionally long strings (25k characters) | | `/(\S+\|\s+)/g` | `/(\r\n\|\n\|\r)/g` | |----------------------|-----------------------|---------------------| | Unit test speed | `1049414ms` (17 min) | `58ms` | | FTR test with 1 rule | `>360000ms` (Timeout) | `2.1 s` | ### Checklist Delete any items that are not applicable to this PR. - [x] [Unit or functional tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html) were updated or added to match the most common scenarios - [ ] [Flaky Test Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was used on any tests changed ### For maintainers - [ ] This was checked for breaking API changes and was [labeled appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#_add_your_labels) - [ ] This will appear in the **Release Notes** and follow the [guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process) --------- Co-authored-by: Elastic Machine Co-authored-by: Georgii Gorbachev (cherry picked from commit 4f6d3570c59d30951368f601b2b59ab3b7a1ae4c) --- .../multi_line_string_diff_algorithm.mock.ts | 64 +++++++++++ .../multi_line_string_diff_algorithm.test.ts | 106 +++++++++++++----- .../multi_line_string_diff_algorithm.ts | 2 +- ...prebuilt_rules.multi_line_string_fields.ts | 56 +++++++++ 4 files changed, 202 insertions(+), 26 deletions(-) create mode 100644 x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.mock.ts diff --git a/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.mock.ts b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.mock.ts new file mode 100644 index 0000000000000..b237a9e3c0dcc --- /dev/null +++ b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.mock.ts @@ -0,0 +1,64 @@ +/* + * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one + * or more contributor license agreements. Licensed under the Elastic License + * 2.0; you may not use this file except in compliance with the Elastic License + * 2.0. + */ + +/** + * Investigation guide, medium size, version A (original). + */ +export const TEXT_M_A = + '## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; + +/** + * Investigation guide, medium size, version B (version A that was modified in one way). + * Modification: last line has been removed. + */ +export const TEXT_M_B = + '## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n'; + +/** + * Investigation guide, medium size, version C (version A that was modified in another way). + * Modification: "Investigating High Number" -> "Investigating Low Number". + */ +export const TEXT_M_C = + '## Triage and analysis\n\n### Investigating Low Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; + +/** + * Investigation guide, medium size, expected result of the algorithm applied to versions A, B, and C. + * Changes compared to version A: + * - last line has been removed + * - "Investigating High Number" -> "Investigating Low Number" + */ +export const TEXT_M_MERGED = + '## Triage and analysis\n\n### Investigating Low Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n'; + +/** + * Investigation guide, extral large size, version A (original). + */ +export const TEXT_XL_A = + '## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; + +/** + * Investigation guide, extral large size, version B (version A that was modified in one way). + * Modification: "Triage and analysis" -> "Triage or analysis". + */ +export const TEXT_XL_B = + '## Triage or analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; + +/** + * Investigation guide, extral large size, version C (version A that was modified in another way). + * Modification: "Investigating High Number" -> "Investigating Low Number". + */ +export const TEXT_XL_C = + '## Triage and analysis\n\n### Investigating Low Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; + +/** + * Investigation guide, extral large size, expected result of the algorithm applied to versions A, B, and C. + * Changes compared to version A: + * - "Triage and analysis" -> "Triage or analysis" + * - "Investigating High Number" -> "Investigating Low Number" + */ +export const TEXT_XL_MERGED = + '## Triage or analysis\n\n### Investigating Low Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n## Triage and analysis\n\n### Investigating High Number of Process and/or Service Terminations\n\nAttackers can stop services and kill processes for a variety of purposes. For example, they can stop services associated with business applications and databases to release the lock on files used by these applications so they may be encrypted, or stop security and backup solutions, etc.\n\nThis rule identifies a high number (10) of service and/or process terminations (stop, delete, or suspend) from the same host within a short time period.\n\n#### Possible investigation steps\n\n- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.\n- Identify the user account that performed the action and whether it should perform this kind of action.\n- Contact the account owner and confirm whether they are aware of this activity.\n- Investigate other alerts associated with the user/host during the past 48 hours.\n- Check if any files on the host machine have been encrypted.\n\n### False positive analysis\n\n- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.\n\n### Response and remediation\n\n- Initiate the incident response process based on the outcome of the triage.\n- Isolate the involved host to prevent further destructive behavior, which is commonly associated with this activity.\n- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.\n- Reimage the host operating system or restore it to the operational state.\n- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.\n- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.\n- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.\n- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).\n'; diff --git a/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.test.ts b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.test.ts index dd1d6abaa04b0..72e87fde6ca2f 100644 --- a/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.test.ts +++ b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.test.ts @@ -13,13 +13,23 @@ import { ThreeWayDiffConflict, } from '../../../../../../../../common/api/detection_engine'; import { multiLineStringDiffAlgorithm } from './multi_line_string_diff_algorithm'; +import { + TEXT_M_A, + TEXT_M_B, + TEXT_M_C, + TEXT_M_MERGED, + TEXT_XL_A, + TEXT_XL_B, + TEXT_XL_C, + TEXT_XL_MERGED, +} from './multi_line_string_diff_algorithm.mock'; describe('multiLineStringDiffAlgorithm', () => { it('returns current_version as merged output if there is no update - scenario AAA', () => { const mockVersions: ThreeVersionsOf = { - base_version: 'My description.\nThis is a second line.', - current_version: 'My description.\nThis is a second line.', - target_version: 'My description.\nThis is a second line.', + base_version: TEXT_M_A, + current_version: TEXT_M_A, + target_version: TEXT_M_A, }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -36,9 +46,9 @@ describe('multiLineStringDiffAlgorithm', () => { it('returns current_version as merged output if current_version is different and there is no update - scenario ABA', () => { const mockVersions: ThreeVersionsOf = { - base_version: 'My description.\nThis is a second line.', - current_version: 'My GREAT description.\nThis is a second line.', - target_version: 'My description.\nThis is a second line.', + base_version: TEXT_M_A, + current_version: TEXT_M_B, + target_version: TEXT_M_A, }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -55,9 +65,9 @@ describe('multiLineStringDiffAlgorithm', () => { it('returns target_version as merged output if current_version is the same and there is an update - scenario AAB', () => { const mockVersions: ThreeVersionsOf = { - base_version: 'My description.\nThis is a second line.', - current_version: 'My description.\nThis is a second line.', - target_version: 'My GREAT description.\nThis is a second line.', + base_version: TEXT_M_A, + current_version: TEXT_M_A, + target_version: TEXT_M_B, }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -74,9 +84,9 @@ describe('multiLineStringDiffAlgorithm', () => { it('returns current_version as merged output if current version is different but it matches the update - scenario ABB', () => { const mockVersions: ThreeVersionsOf = { - base_version: 'My description.\nThis is a second line.', - current_version: 'My GREAT description.\nThis is a second line.', - target_version: 'My GREAT description.\nThis is a second line.', + base_version: TEXT_M_A, + current_version: TEXT_M_B, + target_version: TEXT_M_B, }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -92,20 +102,39 @@ describe('multiLineStringDiffAlgorithm', () => { }); describe('if all three versions are different - scenario ABC', () => { - it('returns a computated merged version without a conflict if 3 way merge is possible', () => { + it('returns a computated merged version with a solvable conflict if 3 way merge is possible (real-world example)', () => { const mockVersions: ThreeVersionsOf = { - base_version: `My description.\f\nThis is a second\u2001 line.\f\nThis is a third line.`, - current_version: `My GREAT description.\f\nThis is a second\u2001 line.\f\nThis is a third line.`, - target_version: `My description.\f\nThis is a second\u2001 line.\f\nThis is a GREAT line.`, + base_version: TEXT_M_A, + current_version: TEXT_M_B, + target_version: TEXT_M_C, }; - const expectedMergedVersion = `My GREAT description.\f\nThis is a second\u2001 line.\f\nThis is a GREAT line.`; + const result = multiLineStringDiffAlgorithm(mockVersions); + + expect(result).toEqual( + expect.objectContaining({ + merged_version: TEXT_M_MERGED, + diff_outcome: ThreeWayDiffOutcome.CustomizedValueCanUpdate, + conflict: ThreeWayDiffConflict.SOLVABLE, + merge_outcome: ThreeWayMergeOutcome.Merged, + }) + ); + }); + + it('returns a computated merged version with a solvable conflict if 3 way merge is possible (simplified example)', () => { + // 3 way merge is possible when changes are made to different lines of text + // (in other words, there are no different changes made to the same line of text). + const mockVersions: ThreeVersionsOf = { + base_version: 'My description.\nThis is a second line.', + current_version: 'My MODIFIED description.\nThis is a second line.', + target_version: 'My description.\nThis is a MODIFIED second line.', + }; const result = multiLineStringDiffAlgorithm(mockVersions); expect(result).toEqual( expect.objectContaining({ - merged_version: expectedMergedVersion, + merged_version: 'My MODIFIED description.\nThis is a MODIFIED second line.', diff_outcome: ThreeWayDiffOutcome.CustomizedValueCanUpdate, conflict: ThreeWayDiffConflict.SOLVABLE, merge_outcome: ThreeWayMergeOutcome.Merged, @@ -113,11 +142,13 @@ describe('multiLineStringDiffAlgorithm', () => { ); }); - it('returns the current_version with a conflict if 3 way merge is not possible', () => { + it('returns the current_version with a non-solvable conflict if 3 way merge is not possible (simplified example)', () => { + // It's enough to have different changes made to the same line of text + // to trigger a NON_SOLVABLE conflict. This behavior is similar to how Git works. const mockVersions: ThreeVersionsOf = { base_version: 'My description.\nThis is a second line.', - current_version: 'My GREAT description.\nThis is a third line.', - target_version: 'My EXCELLENT description.\nThis is a fourth.', + current_version: 'My GREAT description.\nThis is a second line.', + target_version: 'My EXCELLENT description.\nThis is a second line.', }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -131,14 +162,39 @@ describe('multiLineStringDiffAlgorithm', () => { }) ); }); + + it('does not exceed performance limits when diffing and merging extra large input texts', () => { + const mockVersions: ThreeVersionsOf = { + base_version: TEXT_XL_A, + current_version: TEXT_XL_B, + target_version: TEXT_XL_C, + }; + + const startTime = performance.now(); + const result = multiLineStringDiffAlgorithm(mockVersions); + const endTime = performance.now(); + + // If the regex merge in this function takes over 500ms, this test fails + // Performance measurements: https://github.com/elastic/kibana/pull/199388 + expect(endTime - startTime).toBeLessThan(500); + + expect(result).toEqual( + expect.objectContaining({ + merged_version: TEXT_XL_MERGED, + diff_outcome: ThreeWayDiffOutcome.CustomizedValueCanUpdate, + conflict: ThreeWayDiffConflict.SOLVABLE, + merge_outcome: ThreeWayMergeOutcome.Merged, + }) + ); + }); }); describe('if base_version is missing', () => { it('returns current_version as merged output if current_version and target_version are the same - scenario -AA', () => { const mockVersions: ThreeVersionsOf = { base_version: MissingVersion, - current_version: 'My description.\nThis is a second line.', - target_version: 'My description.\nThis is a second line.', + current_version: TEXT_M_A, + target_version: TEXT_M_A, }; const result = multiLineStringDiffAlgorithm(mockVersions); @@ -158,8 +214,8 @@ describe('multiLineStringDiffAlgorithm', () => { it('returns target_version as merged output if current_version and target_version are different - scenario -AB', () => { const mockVersions: ThreeVersionsOf = { base_version: MissingVersion, - current_version: `My GREAT description.\nThis is a second line.`, - target_version: `My description.\nThis is a second line, now longer.`, + current_version: TEXT_M_A, + target_version: TEXT_M_B, }; const result = multiLineStringDiffAlgorithm(mockVersions); diff --git a/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.ts b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.ts index ab830d1b7fc14..e09d8e110bff0 100644 --- a/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.ts +++ b/x-pack/plugins/security_solution/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.ts @@ -102,7 +102,7 @@ const mergeVersions = ({ // TS does not realize that in ABC scenario, baseVersion cannot be missing // Missing baseVersion scenarios were handled as -AA and -AB. const mergedVersion = merge(currentVersion, baseVersion ?? '', targetVersion, { - stringSeparator: /(\S+|\s+)/g, // Retains all whitespace, which we keep to preserve formatting + stringSeparator: /(\r\n|\n|\r)/g, // Separates strings by new lines }); return mergedVersion.conflict diff --git a/x-pack/test/security_solution_api_integration/test_suites/detections_response/rules_management/prebuilt_rules/management/trial_license_complete_tier/upgrade_review_prebuilt_rules.multi_line_string_fields.ts b/x-pack/test/security_solution_api_integration/test_suites/detections_response/rules_management/prebuilt_rules/management/trial_license_complete_tier/upgrade_review_prebuilt_rules.multi_line_string_fields.ts index 55a924cc5e45c..d9c20fc28b43a 100644 --- a/x-pack/test/security_solution_api_integration/test_suites/detections_response/rules_management/prebuilt_rules/management/trial_license_complete_tier/upgrade_review_prebuilt_rules.multi_line_string_fields.ts +++ b/x-pack/test/security_solution_api_integration/test_suites/detections_response/rules_management/prebuilt_rules/management/trial_license_complete_tier/upgrade_review_prebuilt_rules.multi_line_string_fields.ts @@ -10,6 +10,12 @@ import { ThreeWayDiffOutcome, ThreeWayMergeOutcome, } from '@kbn/security-solution-plugin/common/api/detection_engine'; +import { + TEXT_XL_A, + TEXT_XL_B, + TEXT_XL_C, + TEXT_XL_MERGED, +} from '@kbn/security-solution-plugin/server/lib/detection_engine/prebuilt_rules/logic/diff/calculation/algorithms/multi_line_string_diff_algorithm.mock'; import { FtrProviderContext } from '../../../../../../ftr_provider_context'; import { deleteAllTimelines, @@ -249,6 +255,56 @@ export default ({ getService }: FtrProviderContext): void => { expect(reviewResponse.stats.num_rules_with_conflicts).toBe(1); expect(reviewResponse.stats.num_rules_with_non_solvable_conflicts).toBe(0); }); + + it('should handle long multi-line strings without timing out', async () => { + // Install base prebuilt detection rule + await createHistoricalPrebuiltRuleAssetSavedObjects(es, [ + createRuleAssetSavedObject({ + rule_id: 'rule-1', + version: 1, + description: TEXT_XL_A, + }), + ]); + await installPrebuiltRules(es, supertest); + + // Customize a multi line string field on the installed rule + await patchRule(supertest, log, { + rule_id: 'rule-1', + description: TEXT_XL_B, + }); + + // Increment the version of the installed rule, update a multi line string field, and create the new rule assets + const updatedRuleAssetSavedObjects = [ + createRuleAssetSavedObject({ + rule_id: 'rule-1', + version: 2, + description: TEXT_XL_C, + }), + ]; + await createHistoricalPrebuiltRuleAssetSavedObjects(es, updatedRuleAssetSavedObjects); + + // Call the upgrade review prebuilt rules endpoint and check that one rule is eligible for update + // and multi line string field update has no conflict + const reviewResponse = await reviewPrebuiltRulesToUpgrade(supertest); + expect(reviewResponse.rules[0].diff.fields.description).toEqual({ + base_version: TEXT_XL_A, + current_version: TEXT_XL_B, + target_version: TEXT_XL_C, + merged_version: TEXT_XL_MERGED, + diff_outcome: ThreeWayDiffOutcome.CustomizedValueCanUpdate, + merge_outcome: ThreeWayMergeOutcome.Merged, + conflict: ThreeWayDiffConflict.SOLVABLE, + has_update: true, + has_base_version: true, + }); + expect(reviewResponse.rules[0].diff.num_fields_with_updates).toBe(2); + expect(reviewResponse.rules[0].diff.num_fields_with_conflicts).toBe(1); + expect(reviewResponse.rules[0].diff.num_fields_with_non_solvable_conflicts).toBe(0); + + expect(reviewResponse.stats.num_rules_to_upgrade_total).toBe(1); + expect(reviewResponse.stats.num_rules_with_conflicts).toBe(1); + expect(reviewResponse.stats.num_rules_with_non_solvable_conflicts).toBe(0); + }); }); describe('when all versions are not mergable', () => {