Detection rules › Sigma

UAC Bypass Using ChangePK and SLUI

Status
test
Severity
high
Log source
category process_creation, product windows
Author
Christian Burkard (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects an UAC bypass that uses changepk.exe and slui.exe (UACMe 61)

MITRE ATT&CK coverage

Telemetry coverage

Rule body

title: UAC Bypass Using ChangePK and SLUI
id: 503d581c-7df0-4bbe-b9be-5840c0ecc1fc
status: test
description: Detects an UAC bypass that uses changepk.exe and slui.exe (UACMe 61)
references:
    - https://mattharr0ey.medium.com/privilege-escalation-uac-bypass-in-changepk-c40b92818d1b
    - https://github.com/hfiref0x/UACME
    - https://medium.com/falconforce/falconfriday-detecting-uac-bypasses-0xff16-86c2a9107abf
author: Christian Burkard (Nextron Systems)
date: 2021-08-23
modified: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\changepk.exe'
        ParentImage|endswith: '\slui.exe'
        IntegrityLevel:
            - 'High'
            - 'System'
            - 'S-1-16-16384' # System
            - 'S-1-16-12288' # High
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '\changepk.exe'
    ParentImage|endswith: '\slui.exe'
    IntegrityLevel:
        - 'High'
        - 'System'
        - 'S-1-16-16384'
        - 'S-1-16-12288'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Imageends_with
  • \changepk.exe
field:"Image" kind:ends_with value:"\changepk.exe"
IntegrityLeveleq
  • High corpus 21 (sigma 17, kusto 3, splunk 1)
  • S-1-16-12288 corpus 21 (sigma 17, kusto 3, splunk 1)
  • S-1-16-16384 corpus 30 (sigma 22, splunk 4, elastic 3, kusto 1)
  • System corpus 30 (sigma 22, splunk 4, elastic 3, kusto 1)
field:"IntegrityLevel" kind:eq
ParentImageends_with
  • \slui.exe corpus 2 (sigma 2)
field:"ParentImage" kind:ends_with value:"\slui.exe"