diff --git a/detection-rules/attachment_html_recipient_in_javascript_identifiers.yml b/detection-rules/attachment_html_recipient_in_javascript_identifiers.yml
index 849592d655b..92325b3de87 100644
--- a/detection-rules/attachment_html_recipient_in_javascript_identifiers.yml
+++ b/detection-rules/attachment_html_recipient_in_javascript_identifiers.yml
@@ -7,25 +7,29 @@ source: |
type.inbound
and any(attachments,
(
- .file_extension in~ ("html", "htm", "shtml", "dhtml")
+ .file_extension in~ ("html", "htm", "shtml", "dhtml", "xhtml")
or (
.file_extension is null
and .file_type == "unknown"
and .content_type == "application/octet-stream"
- and .size < 100000000
)
or .file_extension in~ $file_extensions_common_archives
or .file_type == "html"
+ or .content_type == "text/html"
)
and any(file.explode(.),
// suspicious identifiers
- any(.scan.javascript.identifiers, strings.like(., "atob", "decrypt"))
- // Recipients address found in javascript
- and any(recipients.to,
- any(..scan.javascript.strings, strings.icontains(., ..email.email))
+ any([.scan.strings.strings, .scan.javascript.identifiers],
+ any(., strings.like(., "*atob*", "*decrypt*"))
)
)
- )
+ // Recipients address found in javascript
+ and any(file.explode(.),
+ any(recipients.to,
+ any(..scan.javascript.strings, strings.icontains(., ..email.email))
+ )
+ )
+ )
attack_types:
- "Credential Phishing"
tactics_and_techniques: