CommentCrew-threat-apt1 | SOC Hunt Feed

Hunt Hypothesis

CommentCrew-threat-apt1 detects potential adversary behavior involving suspicious comment creation or modification in cloud environments, which may indicate reconnaissance or persistence 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 SEASALT_APT1
{

    meta:
        author = "AlienVault Labs"
        info = "CommentCrew-threat-apt1"
      
    strings:
        $s1 = "User-Agent: Mozilla/4.0 (compatible; MSIE 5.00; Windows 98) KSMM" wide ascii
        $s2 = "upfileok" wide ascii
        $s3 = "download ok!" wide ascii
        $s4 = "upfileer" wide ascii
        $s5 = "fxftest" wide ascii

    condition:
        all 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 maintenance job using task scheduler
Filter/Exclusion: process.parent_process_name : "Task Scheduler" or process.name : "schtasks.exe"
Scenario: Admin performing a database backup using SQL Server Agent Job
Filter/Exclusion: process.parent_process_name : "sqlservr.exe" or process.name : "sqlagent.exe"
Scenario: IT staff using PowerShell to generate a report with Out-GridView
Filter/Exclusion: process.name : "powershell.exe" AND process.command_line : "Out-GridView"
Scenario: User running a legitimate script to clean temporary files using cleanmgr.exe
Filter/Exclusion: process.name : "cleanmgr.exe" or process.command_line : "/sagerun:1"
Scenario: System update process using Windows Update with wuauclt.exe
Filter/Exclusion: process.name : "wuauclt.exe" or process.command_line : "/detectnow"