Packanoid10ackanoid

Hunt Hypothesis

This rule detects the presence of the Packanoid10ackanoid YARA signature, which identifies specific malicious or suspicious code patterns often associated with low-severity threats or benign false positives. Proactively hunting for this signature allows the SOC team to validate its relevance in the environment and distinguish between genuine adversary activity and noise, ensuring efficient triage of low-severity alerts.

YARA Rule

rule Packanoid10ackanoid
{
      meta:
		author="malware-lu"
strings:
		$a0 = { BF 00 ?? 40 00 BE [3] 00 E8 9D 00 00 00 B8 [3] 00 8B 30 8B 78 04 BB [3] 00 8B 43 04 91 E3 1F 51 FF D6 56 96 8B 13 8B 02 91 E3 0D 52 51 56 FF D7 5A 89 02 83 C2 04 EB EE 83 C3 08 5E EB DB B9 [2] 00 00 BE 00 [2] 00 EB 01 00 BF [3] 00 }

condition:
		$a0 at pe.entry_point
}

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

• Antivirus/EDR Engine Updates: When security agents (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint, or Symantec) download new signature packs or engine components, these binaries often contain packed or obfuscated code that may match generic packing patterns.
  • Filter/Exclusion: Exclude files located in the vendor-specific installation directories (e.g., C:\Program Files\CrowdStrike\, C:\Program Files\Microsoft Security Client\) and processes running under the service account for the security agent (e.g., CrowdStrike Falcon Service, MsMpEng.exe).
• Java Runtime Environment (JRE) Native Libraries: Enterprise applications relying on Java (e.g., SAP, Oracle, internal web apps) load native libraries like jvm.dll or jli.dll. These are often compiled with specific packing or obfuscation techniques to protect IP or reduce size, which can trigger packing heuristics.
  • Filter/Exclusion: Exclude files with extensions .dll or .so located in standard JRE/JDK paths (e.g., C:\Program Files\Java\, /usr/lib/jvm/) and processes named java.exe or java.
• CI/CD Build Artifacts and Container Images: In DevOps environments, build agents (e.g., Jenkins, GitLab Runner, Azure DevOps) frequently generate or extract compressed archives, container layers, or compiled binaries. These artifacts often use standard compression/packing algorithms (e.g., UPX, LZMA) that YARA rules might flag as “packed.”
  • Filter/Exclusion: Exclude files created by build agent processes (e.g., jenkins.exe, gitlab-runner, vsts-agent) and files located in workspace directories (e.g., C:\jenkins\workspace\, `/var/lib/gitlab