UAC Bypass Using Disk Cleanup — Sigma Rule

Rule metadata and linked tags

Author: Christian Burkard (Nextron Systems). Source status: test; severity: high. Source dates: 2021-08-30 / 2024-12-01.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b0c5e4393e3aafdbb4d49fe105b9a0bafb0e77cfaae2c138b76097e5432fc04d

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: UAC Bypass Using Disk Cleanup
id: b697e69c-746f-4a86-9f59-7bfff8eab881
status: test
description: Detects the pattern of UAC Bypass using scheduled tasks and variable expansion of cleanmgr.exe (UACMe 34)
references:
    - https://github.com/hfiref0x/UACME
author: Christian Burkard (Nextron Systems)
date: 2021-08-30
modified: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|endswith: '"\system32\cleanmgr.exe /autoclean /d C:'
        ParentCommandLine: 'C:\Windows\system32\svchost.exe -k netsvcs -p -s Schedule'
        IntegrityLevel:
            - 'High'
            - 'System'
            - 'S-1-16-16384' # System
            - 'S-1-16-12288' # High
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/hfiref0x/UACME