huntrule

Windows Rundll32 DLL Load via control.exe spawning

Alerts on control.exe spawning rundll32.exe to load Shell32.dll via DLL invocation patterns.

FreeUnreviewedSigmahighv1
title: Windows Rundll32 DLL Load via control.exe spawning
id: 735a749f-4b8c-4450-a95f-7519fee5962d
status: test
description: This rule flags process creation events where a Rundll32 executable is spawned from \\System32\\control.exe. It looks for Rundll32 execution (either by executable name or OriginalFileName) while the command line contains Shell32.dll, a common pattern for indirect DLL loading. The behavior can indicate stealthy execution through legitimate Windows components, and it relies on process creation telemetry including parent image, child image, and command line.
references:
  - https://twitter.com/rikvduijn/status/853251879320662017
  - https://twitter.com/felixw3000/status/853354851128025088
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_rundll32_susp_control_dll_load.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2017-04-15
modified: 2023-02-09
tags:
  - attack.stealth
  - attack.t1218.011
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent:
    ParentImage|endswith: \System32\control.exe
  selection_img:
    - Image|endswith: \rundll32.exe
    - OriginalFileName: RUNDLL32.EXE
  filter:
    CommandLine|contains: Shell32.dll
  condition: all of selection_* and not filter
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: d7eb979b-c2b5-4a6f-a3a7-c87ce6763819
    type: derived

What it detects

This rule flags process creation events where a Rundll32 executable is spawned from \\System32\\control.exe. It looks for Rundll32 execution (either by executable name or OriginalFileName) while the command line contains Shell32.dll, a common pattern for indirect DLL loading. The behavior can indicate stealthy execution through legitimate Windows components, and it relies on process creation telemetry including parent image, child image, and 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.