title: Invoke-Obfuscation Via Use Rundll32
id: a5a30a6e-75ca-4233-8b8c-42e0f2037d3b
description: Detects Obfuscated Powershell via use Rundll32 in Scripts
status: experimental
author: Nikita Nazarov, oscd.community
date: 2019/10/08
references:
    - https://github.com/Neo23x0/sigma/issues/1009
tags:
    - attack.defense_evasion
    - attack.t1027
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    service: powershell
    definition: Script block logging must be enabled for 4104, Module Logging must be enabled for 4103
detection:
    selection_1:
        EventID: 4104
        ScriptBlockText|re: '(?i).*&&.*rundll32.*shell32\.dll.*shellexec_rundll.*(value|invoke|comspec|iex).*"'
    selection_2:
        EventID: 4103
        Payload|re: '(?i).*&&.*rundll32.*shell32\.dll.*shellexec_rundll.*(value|invoke|comspec|iex).*"'
    condition: 1 of them
falsepositives:
    - Unknown
level: high