nSpackV23LiuXingPing

Hunt Hypothesis

This detection identifies the presence of the Liu Xing Ping malware family via YARA signature matching, signaling potential initial access or lateral movement by threat actors utilizing this specific toolset. Proactively hunting for this indicator in Azure Sentinel allows the SOC team to uncover early-stage infections that may evade standard signature-based alerts, enabling faster containment before adversaries establish persistence.

YARA Rule

rule nSpackV23LiuXingPing
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 9C 60 70 61 63 6B 24 40 }

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

Here are 4 specific false positive scenarios for the nSpackV23LiuXingPing detection rule in an enterprise environment:

• Scenario: Automated Endpoint Protection Scans

  • Context: The YARA rule triggers when the corporate endpoint protection agent (e.g., CrowdStrike Falcon or Microsoft Defender for Endpoint) performs a scheduled on-access scan. During these scans, the engine often unpacks and analyzes compressed archives containing legitimate software updates or configuration files that match the nSpack signature pattern.
  • Filter/Exclusion: Create an exclusion based on the process name of the scanner (e.g., falcon.sys, MsMpEng.exe) and exclude any file paths located within the vendor’s installation directory (e.g., C:\Program Files\CrowdStrike\ or C:\ProgramData\Microsoft\Windows Defender\).

• Scenario: Legacy Backup Script Execution

  • Context: A nightly PowerShell script running via Task Scheduler executes a backup routine that utilizes the 7-Zip command-line tool (7z.exe) to compress logs. The rule flags the temporary extraction of these archives as suspicious activity because the nSpack logic detects the specific header structure used by 7-Zip during decompression.
  • Filter/Exclusion: Implement a filter that excludes events where the parent process is svchost.exe (specifically the “Task Scheduler” service) and the file extension is .tmp or located within a designated backup staging folder (e.g., D:\BackupStaging\).

• Scenario: Software Deployment via SCCM/Intune

  • Context: During a mass deployment of a new application update using Microsoft Endpoint Configuration Manager (SCCM) or Intune, the deployment agent extracts installation packages. The rule triggers on