Invoke-Obfuscation Via Use Rundll32 - Security — Sigma Rule

Rule metadata and linked tags

Author: Nikita Nazarov, oscd.community. Source status: test; severity: high. Source dates: 2020-10-09 / 2022-11-29.

{
  "product": "windows",
  "service": "security",
  "definition": "The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: a32966c68587e1111fb33528ee7556a6f05f355435cbeef502a46c69b0b749fc

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Invoke-Obfuscation Via Use Rundll32 - Security
id: cd0f7229-d16f-42de-8fe3-fba365fbcb3a
related:
    - id: 641a4bfb-c017-44f7-800c-2aee0184ce9b
      type: derived
status: test
description: Detects Obfuscated Powershell via use Rundll32 in Scripts
references:
    - https://github.com/SigmaHQ/sigma/issues/1009 # (Task30)
author: Nikita Nazarov, oscd.community
date: 2020-10-09
modified: 2022-11-29
tags:
    - attack.stealth
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    service: security
    definition: The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697
detection:
    selection:
        EventID: 4697
        ServiceFileName|contains|all:
            - '&&'
            - 'rundll32'
            - 'shell32.dll'
            - 'shellexec_rundll'
        ServiceFileName|contains:
            - value
            - invoke
            - comspec
            - iex
    condition: selection
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/SigmaHQ/sigma/issues/1009