Skip to content

Latest commit

 

History

History
99 lines (56 loc) · 3.56 KB

T1191.md

File metadata and controls

99 lines (56 loc) · 3.56 KB
Raw

T1191 - CMSTP

Description from ATT&CK

The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles. (Citation: Microsoft Connection Manager Oct 2009) CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.

Adversaries may supply CMSTP.exe with INF files infected with malicious commands. (Citation: Twitter CMSTP Usage Jan 2018) Similar to Regsvr32 / ”Squiblydoo”, CMSTP.exe may be abused to load and execute DLLs (Citation: MSitPros CMSTP Aug 2017) and/or COM scriptlets (SCT) from remote servers. (Citation: Twitter CMSTP Jan 2018) (Citation: GitHub Ultimate AppLocker Bypass List) (Citation: Endurant CMSTP July 2018) This execution may also bypass AppLocker and other whitelisting defenses since CMSTP.exe is a legitimate, signed Microsoft application.

CMSTP.exe can also be abused to Bypass User Account Control and execute arbitrary commands from a malicious INF through an auto-elevated COM interface. (Citation: MSitPros CMSTP Aug 2017) (Citation: GitHub Ultimate AppLocker Bypass List) (Citation: Endurant CMSTP July 2018)

Atomic Tests


Atomic Test #1 - CMSTP Executing Remote Scriptlet

Adversaries may supply CMSTP.exe with INF files infected with malicious commands

Supported Platforms: Windows

Inputs:

Name Description Type Default Value
inf_file_path Path to the INF file path PathToAtomicsFolder\T1191\src\T1191.inf

Attack Commands: Run with command_prompt!

cmstp.exe /s #{inf_file_path}

Dependencies: Run with powershell!

Description: INF file must exist on disk at specified location (#{inf_file_path})
Check Prereq Commands:
if (Test-Path #{inf_file_path}) {exit 0} else {exit 1}
Get Prereq Commands:
New-Item -Type Directory (split-path #{inf_file_path}) -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1191/src/T1191.inf" -OutFile "#{inf_file_path}"


Atomic Test #2 - CMSTP Executing UAC Bypass

Adversaries may invoke cmd.exe (or other malicious commands) by embedding them in the RunPreSetupCommandsSection of an INF file

Supported Platforms: Windows

Inputs:

Name Description Type Default Value
inf_file_uac Path to the INF file path PathToAtomicsFolder\T1191\src\T1191_uacbypass.inf

Attack Commands: Run with command_prompt!

cmstp.exe /s #{inf_file_uac} /au

Dependencies: Run with powershell!

Description: INF file must exist on disk at specified location (#{inf_file_uac})
Check Prereq Commands:
if (Test-Path #{inf_file_uac}) {exit 0} else {exit 1}
Get Prereq Commands:
New-Item -Type Directory (split-path #{inf_file_uac}) -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1191/src/T1191_uacbypass.inf" -OutFile "#{inf_file_uac}"