Detect Access and Decryption of Group Policy Preference (GPP) Credentials in SYSVOL

ID: DET0381
Domains: Enterprise
Analytics: AN1075
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1075

Correlates file enumeration of XML files in the SYSVOL share with suspicious process execution that decodes or reads encrypted credentials embedded in Group Policy Preference files (e.g., Get-GPPPassword.ps1, gpprefdecrypt.py, Metasploit). Detects abnormal access to \DOMAIN\SYSVOL combined with XML file parsing or decryption logic.

Log Sources
Data Component Name Channel
File Creation (DC0039) WinEventLog:Sysmon EventCode=11
Process Creation (DC0032) WinEventLog:Sysmon EventCode=1
Network Share Access (DC0102) WinEventLog:Security EventCode=5145
Script Execution (DC0029) WinEventLog:PowerShell Scripts with references to XML parsing, AES decryption, or gpprefdecrypt logic
Mutable Elements
Field Description
UserContext Tune to exclude authorized admin users or domain controllers accessing SYSVOL
TimeWindow Adjust for correlation timing between file access and script execution
KnownToolsSignature Extend to include known GPP parsing tool names or script hashes
HostType Distinguish between expected access from DCs vs. lateral movement from workstations