CommentCrew-threat-apt1

Hunt Hypothesis

CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment creation or modification in Azure resources, which may indicate reconnaissance or persistent access. SOC teams should proactively hunt for this behavior to identify early-stage threat activity and prevent lateral movement within the environment.

YARA Rule

rule APT1_WEBC2_CLOVER
{

    meta:
        author = "AlienVault Labs"
        info = "CommentCrew-threat-apt1"
        
    strings:
        $msg1 = "BUILD ERROR!" wide ascii
        $msg2 = "SUCCESS!" wide ascii
        $msg3 = "wild scan" wide ascii
        $msg4 = "Code too clever" wide ascii
        $msg5 = "insufficient lookahead" wide ascii
        $ua1 = "Mozilla/4.0 (compatible; MSIE 6.1; Windows NT 5.1; SV1)" wide ascii
        $ua2 = "Mozilla/5.0 (Windows; Windows NT 5.1; en-US; rv:1.8.0.12) Firefox/1.5.0.12" wide ascii

    condition:
        2 of ($msg*) and 1 of ($ua*)
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 7 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: Scheduled system backup using Veeam Backup & Replication
  Filter/Exclusion: process.name != "vbm.exe" OR process.name != "vmrun.exe"

• Scenario: Admin performing a Windows Update via Group Policy Management Console (GPMC)
  Filter/Exclusion: process.name != "gpmc.msc" OR process.name != "wuauclt.exe"

• Scenario: Database maintenance task using SQL Server Agent Job
  Filter/Exclusion: process.name != "sqlservr.exe" OR process.name != "sqlagent.exe"

• Scenario: User running a PowerShell script for log rotation or cleanup
  Filter/Exclusion: process.name != "powershell.exe" OR script.name != "logrotate.ps1"

• Scenario: IT staff using Ansible to deploy configuration changes across servers
  Filter/Exclusion: process.name != "ansible.exe" OR process.name != "ansible-playbook.exe"