PUNiSHERV15FEUERRADER

Hunt Hypothesis

This YARA rule targets specific memory patterns associated with the PUNiSHERV15FEUERRADER malware variant, indicating the presence of a low-severity threat actor executing known malicious code in memory. Proactively hunting for this signature in Azure Sentinel allows the SOC to identify compromised workloads or containers before the adversary can establish persistence or escalate privileges.

YARA Rule

rule PUNiSHERV15FEUERRADER
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 3F 00 00 80 66 20 ?? 00 7E 20 ?? 00 92 20 ?? 00 A4 20 ?? 00 00 00 00 00 4B 45 52 4E 45 4C 33 32 }

condition:
		$a0
}

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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: A developer or DevOps engineer uses a legitimate binary patching tool (e.g., 010 Editor, HxD, or a custom Python script using lief/pyelftools) to modify the .text section of a C++ application to fix a specific bug or inject a feature flag, causing the file’s checksum and specific byte patterns to match the YARA rule.
  • Filter/Exclusion: Exclude files located in known development directories (e.g., C:\dev\, C:\projects\) or exclude processes initiated by known developer tools (e.g., python.exe, node.exe, code.exe) when the parent process is a recognized IDE or build tool.
• Scenario: A system administrator runs a scheduled PowerShell script to apply a hotfix to a legacy Java application by repackaging the JAR file or modifying class files, where the specific byte sequence targeted by the YARA rule is part of the standard Java bytecode structure or a common library header that coincidentally matches the rule’s condition.
  • Filter/Exclusion: Exclude files with extensions .jar, .class, or .war located in standard application server directories (e.g., C:\Program Files\Tomcat\, C:\opt\apache-tomcat\) or exclude processes named java.exe or javaw.exe when the file path contains lib or classes.
• Scenario: An enterprise endpoint detection tool (e.g., CrowdStrike Falcon, Carbon Black, or SentinelOne) performs an in-memory scan or writes a temporary quarantine copy of a known benign executable to a specific temporary folder, and the YARA rule matches the specific header or metadata of that temporary file due to the tool’s proprietary packaging format.
  • Filter/Exclusion: Exclude files located in vendor-specific temporary directories (e.g