PowerShell module: Obfuscated Invoke via rundll32/shell32.dll comspec iex patterns

Flags PowerShell module payloads containing obfuscated rundll32 shell32.dll shellexec_rundll invocation patterns.

FreeReviewedSigma · High · v2

Product: windows
Category: ps_module
Author: Nikita Nazarov, oscd.community (SigmaHQ), DRL 1.1
Published: 2019-10-08
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 identifies PowerShell module payloads containing a set of obfuscation and execution indicators, including &&, rundll32, shell32.dll, shellexec_rundll, and the combination of value, invoke, comspec, and iex. Attackers may use these mixed command-and-script patterns to trigger indirect execution and hinder straightforward inspection. It relies on PowerShell module telemetry where the Payload field is available to match the specified string fragments.

Reporting behind it

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PowerShell module: Obfuscated Invoke via rundll32/shell32.dll comspec iex patterns

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-obfuscated-invoke-using-rundll32-and-shell32-dll-88a22f69

title: "PowerShell module: Obfuscated Invoke via rundll32/shell32.dll comspec iex patterns"
id: ce46b2c9-0cbf-4c37-8c7b-fdefb3125bfd
related:
  - id: a5a30a6e-75ca-4233-8b8c-42e0f2037d3b
    type: derived
  - id: 88a22f69-62f9-4b8a-aa00-6b0212f2f05a
    type: derived
status: test
description: This rule identifies PowerShell module payloads containing a set of obfuscation and execution indicators, including &&, rundll32, shell32.dll, shellexec_rundll, and the combination of value, invoke, comspec, and iex. Attackers may use these mixed command-and-script patterns to trigger indirect execution and hinder straightforward inspection. It relies on PowerShell module telemetry where the Payload field is available to match the specified string fragments.
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_use_rundll32.yml
author: Nikita Nazarov, oscd.community, Huntrule Team
date: 2019-10-08
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
      - shell32.dll
      - shellexec_rundll
    Payload|contains:
      - value
      - invoke
      - comspec
      - iex
  condition: selection_4103
falsepositives:
  - Unknown
level: high
license: DRL-1.1

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