CommentCrew-threat-apt1 | SOC Hunt Feed

Hunt Hypothesis

CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment creation or modification in Azure resources, which may indicate reconnaissance or persistence activities. SOC teams should proactively hunt for this behavior to identify early-stage threats and prevent lateral movement or data exfiltration in their Azure Sentinel environment.

YARA Rule

rule APT1_WEBC2_AUSOV
{

    meta:
        author = "AlienVault Labs"
        info = "CommentCrew-threat-apt1"
        
    strings:
        $1 = "ntshrui.dll" wide ascii
        $2 = "%SystemRoot%\\System32\\" wide ascii
        $3 = "<!--DOCHTML" wide ascii
        $4 = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)" wide ascii
        $5 = "Ausov" wide ascii

    condition:
        4 of them
}

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 5 string patterns in its detection logic.

Source Rule

False Positive Guidance

Scenario: Scheduled system backup using Veeam Backup & Replication
Filter/Exclusion: process.name != "VeeamBackup.exe" or check for process.parent.name == "vmtoolsd.exe" or process.parent.name == "vmware-authd.exe"
Scenario: Admin performing Windows Update via Group Policy
Filter/Exclusion: process.name != "wuauclt.exe" or check for process.parent.name == "services.exe" and process.command_line contains "GroupPolicy"
Scenario: Running PowerShell scripts for routine system monitoring
Filter/Exclusion: process.name != "powershell.exe" or check for process.command_line contains "Invoke-Command" and process.parent.name == "taskeng.exe"
Scenario: SQL Server Agent Jobs executing maintenance tasks
Filter/Exclusion: process.name != "sqlagent.exe" or check for process.parent.name == "sqlservr.exe" and process.command_line contains "SQLAgent -start"
Scenario: Ansible playbook execution for configuration management
Filter/Exclusion: process.name != "ansible.exe" or check for process.parent.name == "systemd.exe" and process.command_line contains "ansible-playbook"