SigmaHQ/rules/windows/sysmon/sysmon_wmi_susp_scripting.yml

title: Suspicious Scripting in a WMI Consumer
id: fe21810c-2a8c-478f-8dd3-5a287fb2a0e0
status: experimental
description: Detects suspicious scripting in WMI Event Consumers
author: Florian Roth
references:
    - https://in.security/an-intro-into-abusing-and-identifying-wmi-event-subscriptions-for-persistence/
    - https://github.com/Neo23x0/signature-base/blob/master/yara/gen_susp_lnk_files.yar#L19
date: 2019/04/15
tags:
    - attack.t1086          # an old one
    - attack.execution
    - attack.t1059.005
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 20
        Destination|contains:
            - 'new-object system.net.webclient).downloadstring('
            - 'new-object system.net.webclient).downloadfile('
            - 'new-object net.webclient).downloadstring('
            - 'new-object net.webclient).downloadfile('
            - ' iex('
            - 'WScript.shell'
            - ' -nop '
            - ' -noprofile '
            - ' -decode '
            - ' -enc '
    condition: selection
fields:
    - CommandLine
    - ParentCommandLine
falsepositives:
    - Administrative scripts
level: high