Detects a certain type of Enfal Malware

Hunt Hypothesis

The hypothesis is that the detection identifies Enfal Malware leveraging stealthy fileless execution techniques to evade traditional endpoint defenses. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and contain advanced persistent threats before they escalate and exfiltrate sensitive data.

YARA Rule

rule Enfal_Malware {
	meta:
		description = "Detects a certain type of Enfal Malware"
		author = "Florian Roth"
		reference = "not set"
		date = "2015/02/10"
		hash = "9639ec9aca4011b2724d8e7ddd13db19913e3e16"
		score = 60
	strings:
		$s0 = "POWERPNT.exe" fullword ascii
		$s1 = "%APPDATA%\\Microsoft\\Windows\\" fullword ascii
		$s2 = "%HOMEPATH%" fullword ascii
		$s3 = "Server2008" fullword ascii
		$s4 = "Server2003" fullword ascii
		$s5 = "Server2003R2" fullword ascii
		$s6 = "Server2008R2" fullword ascii
		$s9 = "%HOMEDRIVE%" fullword ascii
		$s13 = "%ComSpec%" fullword 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 9 string patterns in its detection logic.

References

• not set
• Source Rule

False Positive Guidance

• Scenario: A system administrator is using PowerShell to automate the deployment of a legitimate software update.
  Filter/Exclusion: Check for the presence of known administrative tools or scripts in the command line context, such as powershell.exe -Command with a known update script path.

• Scenario: A scheduled job runs Task Scheduler to perform routine system maintenance, including disk cleanup or log rotation.
  Filter/Exclusion: Exclude processes initiated by the Task Scheduler service or those with a known job name or command line that matches standard maintenance tasks.

• Scenario: A security analyst is using Wireshark to capture and analyze network traffic for a security investigation.
  Filter/Exclusion: Filter out processes associated with Wireshark or any network analysis tool, or check for the presence of a known analyst tool in the process tree.

• Scenario: A database administrator is using SQL Server Management Studio (SSMS) to run a query that inadvertently triggers the detection due to a similar string in the query.
  Filter/Exclusion: Exclude processes launched from SSMS or those with a command line containing known SQL Server paths or query patterns.

• Scenario: A developer is using Visual Studio to debug a script that includes a string matching the malware signature due to a naming convention.
  Filter/Exclusion: Exclude processes associated with Visual Studio or those running in a development environment with known project or script naming patterns.