Detection rules › Sigma
Access To Potentially Sensitive Sysvol Files By Uncommon Applications
Detects file access requests to potentially sensitive files hosted on the Windows Sysvol share.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access |
Rule body
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
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_*Stage 1: selection
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'
Stage 2: not filter_main_*
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'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Image | eq | C:\Windows\explorer.exe | excludes:Image field:"Image" value:"C:\Windows\explorer.exe" |
Image | starts_with | C:\Program Files (x86)\ | excludes:Image field:"Image" value:"C:\Program Files (x86)\" |
Image | starts_with | C:\Program Files\ | excludes:Image field:"Image" value:"C:\Program Files\" |
Image | starts_with | C:\Windows\SysWOW64\ | excludes:Image field:"Image" value:"C:\Windows\SysWOW64\" |
Image | starts_with | C:\Windows\system32\ | excludes:Image field:"Image" value:"C:\Windows\system32\" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
FileName | ends_with |
| field:"file_name" kind:ends_with |
FileName | match |
| field:"file_name" kind:match |
FileName | starts_with |
| field:"file_name" kind:starts_with value:"\\" |