Detection rules › Sigma
Access To Sysvol Policies Share By Uncommon Process
Detects file access requests to the Windows Sysvol Policies Share by uncommon processes
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access |
Rule body
title: Access To Sysvol Policies Share By Uncommon Process
id: 8344c19f-a023-45ff-ad63-a01c5396aea0
status: test
description: Detects file access requests to the Windows Sysvol Policies Share by uncommon processes
references:
- https://github.com/vletoux/pingcastle
author: frack113
date: 2023-12-21
tags:
- attack.credential-access
- attack.t1552.006
- detection.threat-hunting
logsource:
category: file_access
product: windows
definition: 'Requirements: Microsoft-Windows-Kernel-File ETW provider'
detection:
selection:
FileName|startswith: '\\'
FileName|contains|all:
- '\sysvol\'
- '\Policies\'
filter_main_generic:
Image|contains:
- ':\Program Files (x86)\'
- ':\Program Files\'
- ':\Windows\explorer.exe'
- ':\Windows\system32\'
- ':\Windows\SysWOW64\'
condition: selection and not 1 of filter_main_*
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
selection:
FileName|startswith: '\\'
FileName|contains|all:
- '\sysvol\'
- '\Policies\'
Stage 2: not filter_main_generic
filter_main_generic:
Image|contains:
- ':\Program Files (x86)\'
- ':\Program Files\'
- ':\Windows\explorer.exe'
- ':\Windows\system32\'
- ':\Windows\SysWOW64\'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Image | match | :\Program Files (x86)\ | excludes:Image field:"Image" value:":\Program Files (x86)\" |
Image | match | :\Program Files\ | excludes:Image field:"Image" value:":\Program Files\" |
Image | match | :\Windows\SysWOW64\ | excludes:Image field:"Image" value:":\Windows\SysWOW64\" |
Image | match | :\Windows\explorer.exe | excludes:Image field:"Image" value:":\Windows\explorer.exe" |
Image | match | :\Windows\system32\ | excludes:Image field:"Image" value:":\Windows\system32\" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
FileName | match |
| field:"file_name" kind:match |
FileName | starts_with |
| field:"file_name" kind:starts_with value:"\\" |