Access To Potentially Sensitive Sysvol Files By Uncommon Applications — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: medium. Source dates: 2023-12-21 / 2024-07-29.

{
  "category": "file_access",
  "product": "windows",
  "definition": "Requirements: Microsoft-Windows-Kernel-File ETW provider"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: dea42aed13f7c28f07542f5eb14fcbb61a20296d10780839eaa32ca6bff631fb

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Access To Potentially Sensitive Sysvol Files By Uncommon Applications
id: d51694fe-484a-46ac-92d6-969e76d60d10
related:
    - id: 8344c19f-a023-45ff-ad63-a01c5396aea0
      type: derived
status: test
description: Detects file access requests to potentially sensitive files hosted on the Windows Sysvol share.
references:
    - https://github.com/vletoux/pingcastle
author: frack113
date: 2023-12-21
modified: 2024-07-29
tags:
    - attack.credential-access
    - attack.t1552.006
logsource:
    category: file_access
    product: windows
    definition: 'Requirements: Microsoft-Windows-Kernel-File ETW provider'
detection:
    selection:
        FileName|startswith: '\\'
        FileName|contains|all:
            - '\sysvol\'
            - '\Policies\'
        FileName|endswith:
            - 'audit.csv'
            - 'Files.xml'
            - 'GptTmpl.inf'
            - 'groups.xml'
            - 'Registry.pol'
            - 'Registry.xml'
            - 'scheduledtasks.xml'
            - 'scripts.ini'
            - 'services.xml'
    filter_main_generic:
        Image|startswith:
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
            - 'C:\Windows\system32\'
            - 'C:\Windows\SysWOW64\'
    filter_main_explorer:
        Image: 'C:\Windows\explorer.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/vletoux/pingcastle