PowerShell module activity launching rundll32 via shell32.dll obfuscation content

Alerts when PowerShell module payloads reference a shell32/rundll32 launcher pattern that includes PowerShell.

FreeReviewedSigma · Medium · v2

Product: windows
Category: ps_module
Author: Timur Zinniatullin, oscd.community (SigmaHQ), DRL 1.1
Published: 2020-10-18
Updated: 2026-07-31

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
- T1027Obfuscated Files or Information
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows PowerShell module events where the module payload contains all of the strings rundll32.exe, shell32.dll, shellexec_rundll, and powershell. Attackers may use rundll32 execution paths and DLL-related routines to obscure process intent while still invoking PowerShell. The detection relies on telemetry that records the PowerShell module payload content.

Reporting behind it

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PowerShell module activity launching rundll32 via shell32.dll obfuscation content

Pivot detection · T1027 · 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.

powershell-module-logging-rundll32-shell32-obfuscation-with-powershell-a23791fe

title: PowerShell module activity launching rundll32 via shell32.dll obfuscation content
id: 1f74940e-5644-4756-a8b3-26cce8bb9c8b
related:
  - id: e6cb92b4-b470-4eb8-8a9d-d63e8583aae0
    type: derived
  - id: a23791fe-8846-485a-b16b-ca691e1b03d4
    type: derived
status: test
description: This rule flags Windows PowerShell module events where the module payload contains all of the strings rundll32.exe, shell32.dll, shellexec_rundll, and powershell. Attackers may use rundll32 execution paths and DLL-related routines to obscure process intent while still invoking PowerShell. The detection relies on telemetry that records the PowerShell module payload content.
references:
  - https://github.com/SigmaHQ/sigma/issues/1009
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_module/posh_pm_invoke_obfuscation_via_rundll.yml
author: Timur Zinniatullin, oscd.community, Huntrule Team
date: 2020-10-18
modified: 2022-11-29
tags:
  - attack.stealth
  - attack.t1027
  - attack.execution
  - attack.t1059.001
logsource:
  product: windows
  category: ps_module
  definition: 0ad03ef1-f21b-4a79-8ce8-e6900c54b65b
detection:
  selection_4103:
    Payload|contains|all:
      - rundll32.exe
      - shell32.dll
      - shellexec_rundll
      - powershell
  condition: selection_4103
falsepositives:
  - Unknown
level: medium
license: DRL-1.1

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