Iron Tiger Malware - Ring Gh0stvariant

Hunt Hypothesis

The detection identifies potential Iron Tiger Malware activity associated with the Ring Gh0stvariant, leveraging unusual process execution patterns indicative of adversarial behavior. SOC teams should proactively hunt for this behavior in Azure Sentinel to detect and mitigate early-stage malware infections that may evade traditional detection methods.

YARA Rule

rule IronTiger_Ring_Gh0stvariant
{
  
    meta:
        author = "Cyber Safety Solutions, Trend Micro"
        description = "Iron Tiger Malware - Ring Gh0stvariant"
        reference = "http://goo.gl/T5fSJC"
  
    strings:
        $str1 = "RING RAT Exception" nocase wide ascii
        $str2 = "(can not update server recently)!" nocase wide ascii
        $str4 = "CreaetProcess Error" nocase wide ascii
        $bla1 = "Sucess!" nocase wide ascii
        $bla2 = "user canceled!" nocase wide ascii
  
    condition:
        uint16(0) == 0x5a4d and ((any of ($str*)) or (all of ($bla*)))
}

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.

References

• http://goo.gl/T5fSJC
• Source Rule

False Positive Guidance

• Scenario: Scheduled system maintenance or patching using Windows Update or Group Policy Preferences (GPP)
  Filter/Exclusion: Check for EventID 6008 (Event Log service stopped) or EventID 6006 (Event Log service started) in conjunction with known patching schedules. Exclude processes associated with wuauclt.exe or gupdate.exe.

• Scenario: PowerShell script execution for routine system monitoring or log analysis using PowerShell ISE or PowerShell Core
  Filter/Exclusion: Filter by ProcessName containing powershell.exe and check for known legitimate scripts in the C:\Windows\System32\WindowsPowerShell\v1.0\ directory. Exclude scripts with known benign command-line arguments.

• Scenario: Scheduled Task running a legitimate Windows Defender or Microsoft Defender ATP scan
  Filter/Exclusion: Filter by ProcessName containing MsMpEng.exe or MsMpCmdRun.exe. Exclude tasks with the Microsoft Defender or Windows Defender task name in the task scheduler.

• Scenario: Administrative tool usage such as Windows Server Manager or Server Manager for configuration changes
  Filter/Exclusion: Filter by ProcessName containing ServerManager.exe or smigui.exe. Exclude processes initiated from known administrative consoles or via mmc.exe with legitimate snap-ins.

• Scenario: Log collection or monitoring tool such as Splunk or ELK Stack running a background process for data ingestion
  Filter/Exclusion: Filter by ProcessName containing splunkd.exe, logstash.exe, or beats.exe. Exclude processes that match known log collection tool service names and are running under the appropriate service account.