Rule to detect Shamoon malware http://goo.gl/QTxohN

Hunt Hypothesis

This hunt targets adversaries deploying the Shamoon malware family, which is known for targeting industrial control systems and executing destructive payloads via HTTP-based command-and-control communications. Proactively hunting for these specific network signatures in Azure Sentinel is critical to identify early-stage infections before they escalate into widespread operational disruptions or data destruction events.

YARA Rule

rule CrowdStrike_Shamoon_DroppedFile { 
	meta:
		description = "Rule to detect Shamoon malware http://goo.gl/QTxohN"
		reference = "http://www.rsaconference.com/writable/presentations/file_upload/exp-w01-hacking-exposed-day-of-destruction.pdf"
	strings:
		$testn123 = "test123" wide
		$testn456 = "test456" wide
		$testn789 = "test789" wide
		$testdomain = "testdomain.com" wide $pingcmd = "ping -n 30 127.0.0.1 >nul" wide
	condition:
		(any of ($testn*) or $pingcmd) and $testdomain
}

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://www.rsaconference.com/writable/presentations/file_upload/exp-w01-hacking-exposed-day-of-destruction.pdf
• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the Shamoon Malware detection rule in an enterprise environment, along with recommended filters or exclusions:

• Automated Firmware Updates on Industrial Control Systems (ICS)

  • Scenario: Scheduled maintenance jobs using tools like Siemens TIA Portal or Rockwell FactoryTalk push firmware updates to PLCs and SCADA devices. These updates often involve writing executable binaries directly to specific system directories (e.g., C:\Program Files\Siemens) and modifying registry keys, which mimics the file creation and persistence mechanisms of Shamoon.
  • Filter/Exclusion: Exclude network traffic and host events originating from known ICS management subnets or specific service accounts (e.g., svc_automation_update) accessing standard firmware vendor paths.

• Enterprise Endpoint Protection Scanning

  • Scenario: The organization’s antivirus solution, such as CrowdStrike Falcon, Microsoft Defender for Endpoint, or Symantec Endpoint Protection, performs deep integrity scans. During these scans, the EDR agent may temporarily create shadow copies of executable files in temporary folders (e.g., C:\Windows\Temp) and modify file permissions to analyze them, triggering the rule’s signature for suspicious binary execution.
  • Filter/Exclusion: Create an exclusion for processes matching the known EDR service names (e.g., MsMpEng.exe, FalconSensor.exe) when they interact with temporary directories or specific quarantine paths defined in the security policy.

• Software Deployment via Configuration Management

  • Scenario: IT administrators use Microsoft SCCM (Configuration Manager) or Ansible to deploy new applications or patches across the fleet. These tools often execute PowerShell scripts that download .exe installers, extract them to staging folders, and launch silent installations (/quiet, /norestart),