CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment-based PowerShell scripts that may be used for initial access or command and control. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage threats from unknown or evolving attack tactics.
YARA Rule
rule APT1_WEBC2_UGX
{
meta:
author = "AlienVault Labs"
info = "CommentCrew-threat-apt1"
strings:
$persis = "SOFTWARE\\MICROSOFT\\WINDOWS\\CURRENTVERSION\\RUN" wide ascii
$exe = "DefWatch.exe" wide ascii
$html = "index1.html" wide ascii
$cmd1 = "!@#tiuq#@!" wide ascii
$cmd2 = "!@#dmc#@!" wide ascii
$cmd3 = "!@#troppusnu#@!" wide ascii
condition:
3 of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 6 string patterns in its detection logic.
Scenario: A system administrator is using PowerShell to automate the deployment of a software update via Group Policy.
Filter/Exclusion: Exclude events where the process is powershell.exe and the command line includes GroupPolicy or gpupdate.
Scenario: A scheduled job runs SQL Server Agent to perform a nightly backup of a database.
Filter/Exclusion: Exclude events where the process is sqlservr.exe and the command line includes backup or sqlbackup.
Scenario: An IT technician is using Windows Task Scheduler to run a script that configures firewall rules.
Filter/Exclusion: Exclude events where the process is schtasks.exe and the command line includes firewall or netsh.
Scenario: A DevOps engineer is using Ansible to configure a server, which includes commenting in configuration files.
Filter/Exclusion: Exclude events where the process is ansible.exe and the command line includes ansible-playbook or configure.
Scenario: A database administrator is using MySQL Workbench to execute a script that comments out old queries for archival.
Filter/Exclusion: Exclude events where the process is mysql.exe and the command line includes --comment or --skip-comments.