Windows Process Creation: Empire PowerShell UAC Bypass CommandLine Pattern

Flags Windows process creation events running Empire-style PowerShell UAC bypass command fragments.

FreeReviewedSigma · Critical · v2

Product: windows
Category: process_creation
Author: Ecco (SigmaHQ), DRL 1.1
Published: 2019-08-30
Updated: 2026-07-31

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1548.002Bypass User Account Control
Defense Evasion
- T1548.002Bypass User Account Control
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule matches PowerShell command lines that include a specific pattern used to set a variable from the HKCU\Software\Microsoft\Windows Update\Update registry value, consistent with some Empire PowerShell UAC bypass methods. Attackers use UAC bypass techniques to elevate privileges and execute subsequent actions with higher integrity. The detection relies on process creation telemetry and command-line contents containing the exact substrings defined in the rule.

Reporting behind it

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Malicious Cloud Atlas UAC Bypass via fodhelper (via process_creation)

Suspicious computerdefaults.exe Spawning Child Process

Suspicious UAC Bypass via control.exe App Paths or Shell Open Command Hijack

Malicious UAC Bypass via COMAutoApprovalList Registry Modification (via registry_set)

Suspicious UAC Bypass via COMAutoApprovalList Registry Modification (via registry_set)

Malicious UAC Bypass via explorer.exe NOUACCHECK Argument

Suspicious UAC Bypass via ms-settings Shell Command Hijack (via registry_set)

Windows Process Creation: Empire PowerShell UAC Bypass CommandLine Pattern

Pivot detection · T1548.002 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

windows-empire-powershell-uac-bypass-command-line-patterns-3268b746

title: "Windows Process Creation: Empire PowerShell UAC Bypass CommandLine Pattern"
id: ebc985ea-267a-4a32-b1c8-e8ae2d98f837
status: stable
description: This rule matches PowerShell command lines that include a specific pattern used to set a variable from the HKCU\Software\Microsoft\Windows Update\Update registry value, consistent with some Empire PowerShell UAC bypass methods. Attackers use UAC bypass techniques to elevate privileges and execute subsequent actions with higher integrity. The detection relies on process creation telemetry and command-line contents containing the exact substrings defined in the rule.
references:
  - https://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/data/module_source/privesc/Invoke-EventVwrBypass.ps1#L64
  - https://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/data/module_source/privesc/Invoke-FodHelperBypass.ps1#L64
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_empire_powershell_uac_bypass.yml
author: Ecco, Huntrule Team
date: 2019-08-30
modified: 2023-02-21
tags:
  - attack.privilege-escalation
  - attack.t1548.002
  - car.2019-04-001
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    CommandLine|contains:
      - " -NoP -NonI -w Hidden -c $x=$((gp HKCU:Software\\Microsoft\\Windows Update).Update)"
      - " -NoP -NonI -c $x=$((gp HKCU:Software\\Microsoft\\Windows Update).Update);"
  condition: selection
falsepositives:
  - Unknown
level: critical
license: DRL-1.1
related:
  - id: 3268b746-88d8-4cd3-bffc-30077d02c787
    type: derived

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