Windows UAC Bypass via msconfig Token Modification (msconfig.exe -5) Process Creation

Flags msconfig.exe invoked with -5 from a Temp pkgmgr.exe parent under elevated integrity levels, indicating a possible UAC bypass.

FreeUnreviewedSigmahighv1

windows-uac-bypass-via-msconfig-token-modification-msconfig-exe-5-process-creati-ad92e3f9

title: Windows UAC Bypass via msconfig Token Modification (msconfig.exe -5) Process Creation
id: 5da8a289-c3de-4732-b71f-4de65fb67e89
status: test
description: This rule identifies Windows process creations where msconfig.exe is launched with the "-5" argument and the spawning process appears to come from a Temp package manager binary path. It further constrains matches to processes running with high, system, or S-1-16 elevated integrity levels, consistent with attempts to elevate privileges via a UAC bypass technique. The detection relies on process creation telemetry including integrity level, parent process image path, and full command line.
references:
  - https://github.com/hfiref0x/UACME
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_uac_bypass_msconfig_gui.yml
author: Christian Burkard (Nextron Systems), Huntrule Team
date: 2021-08-30
modified: 2024-12-01
tags:
  - attack.privilege-escalation
  - attack.t1548.002
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    IntegrityLevel:
      - High
      - System
      - S-1-16-16384
      - S-1-16-12288
    ParentImage|endswith: \AppData\Local\Temp\pkgmgr.exe
    CommandLine: '"C:\Windows\system32\msconfig.exe" -5'
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: ad92e3f9-7eb6-460e-96b1-582b0ccbb980
    type: derived

What it detects

This rule identifies Windows process creations where msconfig.exe is launched with the "-5" argument and the spawning process appears to come from a Temp package manager binary path. It further constrains matches to processes running with high, system, or S-1-16 elevated integrity levels, consistent with attempts to elevate privileges via a UAC bypass technique. The detection relies on process creation telemetry including integrity level, parent process image path, and full command line.

Known false positives

Unknown

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.