SigmaHQ/rules/windows/builtin/win_susp_rundll32_activity.yml

title: Detects Suspicious Rundll32 activity
description: Detects suspicious process related to rundll32 based on arguments
status: experimental
reference: 
    - http://www.hexacorn.com/blog/2017/05/01/running-programs-via-proxy-jumping-on-a-edr-bypass-trampoline/
    - https://twitter.com/Hexacorn/status/885258886428725250
    - https://gist.github.com/ryhanson/227229866af52e2d963cf941af135a52
author: juju4
logsource:
    product: windows
    service: security
    description: 'Requirements: Audit Policy : Detailed Tracking > Audit Process creation, Group Policy : Administrative Templates\System\Audit Process Creation'
detection:
    selection:
        EventID: 4688
        CommandLine: 
            # match with or without rundll32.exe to try to catch evasion
            - '*\rundll32.exe* url.dll,*OpenURL *'
            - '*\rundll32.exe* url.dll,*OpenURLA *'
            - '*\rundll32.exe* url.dll,*FileProtocolHandler *'
            - '*\rundll32.exe* zipfldr.dll,*RouteTheCall *'
            - '*\rundll32.exe* Shell32.dll,*Control_RunDLL *'
            - '*\rundll32.exe javascript:*'
            - '* url.dll,*OpenURL *'
            - '* url.dll,*OpenURLA *'
            - '* url.dll,*FileProtocolHandler *'
            - '* zipfldr.dll,*RouteTheCall *'
            - '* Shell32.dll,*Control_RunDLL *'
            - '* javascript:*'
            - '*.RegisterXLL*'
    condition: selection
falsepositives: 
    - False positives depend on scripts and administrative tools used in the monitored environment
level: medium