CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment creation or manipulation in cloud environments, which may indicate reconnaissance or initial compromise activities. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify early-stage threats and prevent lateral movement or data exfiltration.
YARA Rule
rule ccrewSSLBack2
{
meta:
author = "AlienVault Labs"
info = "CommentCrew-threat-apt1"
strings:
$a = {39 82 49 42 BE 1F 3A}
condition:
any of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Scenario: Scheduled System Maintenance Job
Description: A legitimate scheduled task runs a script that includes a comment containing “Crew” or similar text, such as # Crew maintenance script.
Filter/Exclusion: Exclude tasks with command_line containing schtasks or at and where the script path is in a known system directory (e.g., C:\Windows\System32\).
Scenario: Admin Task for User Management
Description: An administrator uses PowerShell to add a user with a comment field that includes the word “Crew”, such as Add-ADUser -Comment "Crew Admin".
Filter/Exclusion: Exclude events where the source is a known admin tool (e.g., AD Users and Computers) and the comment field is part of a user management task.
Scenario: Log File Parsing with Comment Tags
Description: A log parsing script or tool (e.g., LogParser, Splunk) includes a comment tag like <!-- Crew: Log entry --> in its configuration or output.
Filter/Exclusion: Exclude entries where the source is a log parsing tool or where the content is part of a configuration file (e.g., *.config, *.log, *.xml).
Scenario: Backup Script with Version Comments
Description: A backup script (e.g., Veeam, Acronis) includes a comment in the script indicating the version or build, such as # Crew Backup v2.3.
Filter/Exclusion: Exclude scripts located in backup directories (e.g., C:\Backup\, D:\Backups\) or where the command line includes backup, restore, or snapshot.
Scenario: Internal Documentation with Comment Tags
Description: An internal documentation