Windows Process Creation: Empire PowerShell UAC Bypass CommandLine Pattern
Flags Windows process creation events running Empire-style PowerShell UAC bypass command fragments.
- 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 EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Defense Evasion
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
- github.comhttps://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/data/module_source/privesc/Invoke-EventVwrBypass.ps1#L64
- github.comhttps://github.com/EmpireProject/Empire/blob/e37fb2eef8ff8f5a0a689f1589f424906fe13055/data/module_source/privesc/Invoke-FodHelperBypass.ps1#L64
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_empire_powershell_uac_bypass.yml
Changelog
v2- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
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