gh0st

Hunt Hypothesis

This detection identifies the execution of the “gh0st” malware signature via YARA scanning, indicating potential adversary activity involving known threat artifacts within the environment. Proactively hunting for this indicator in Azure Sentinel is essential to validate its presence across endpoints and determine if it represents a benign false positive or an early-stage intrusion requiring further investigation despite its low severity rating.

YARA Rule

rule gh0st

{

meta:
	author = "https://github.com/jackcr/"

   strings:
      $a = { 47 68 30 73 74 ?? ?? ?? ?? ?? ?? ?? ?? 78 9C }
      $b = "Gh0st Update"

   condition:
      any 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 2 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the gh0st detection rule in an enterprise environment, including suggested filters and exclusions:

• Antivirus Real-Time Scanning of Compressed Archives

  • Scenario: Enterprise endpoint protection suites (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint) frequently scan large .zip or .tar.gz files containing software installers. The gh0st YARA rule may flag the internal structure of these archives if they contain specific PE headers or resource sections that mimic the loader behavior of the Gh0st RAT, particularly when scanning files in temporary directories (%TEMP%).
  • Filter/Exclusion: Exclude processes matching the AV engine’s executable name (e.g., MsMpEng.exe, Csfalcon.exe) and filter out detections where the file path contains \Temp\ or \AppData\Local\Temp\.

• Software Deployment via SCCM or Intune

  • Scenario: During scheduled maintenance windows, deployment agents like Microsoft Endpoint Configuration Manager (SCCM) or Intune Management Extension extract application packages to the C:\Windows\CCMCache directory. If the deployed software includes a custom installer that utilizes similar code signatures or resource structures as the Gh0st payload, the YARA rule will trigger on every deployment cycle across thousands of endpoints.
  • Filter/Exclusion: Create an exclusion for processes running under the ccmexec.exe service account and filter file paths starting with C:\Windows\CCMCache\. Additionally, whitelist specific SHA-256 hashes known to be part of standard deployment packages.

• Scheduled PowerShell Script Execution

  • Scenario: IT administrators often run scheduled tasks (via Task Scheduler) that utilize PowerShell (powershell.exe) to execute inventory scripts or configuration