title: PowerShell ShellCode
status: experimental
description: Detects Base64 encoded Shellcode
references:
    - https://twitter.com/cyb3rops/status/1063072865992523776
tags:
    - attack.privilege_escalation
    - attack.execution
    - attack.t1055
    - attack.t1086
author: David Ledbetter (shellcode), Florian Roth (rule)
date: 2018/11/17
logsource:
    product: windows
    service: powershell
    description: 'Script block logging must be enabled'
detection:
    selection:
        EventID: 4104
    keyword1: 
        - '*AAAAYInlM*'
    keyword2: 
        - '*OiCAAAAYInlM*'
        - '*OiJAAAAYInlM*'
    condition: selection and keyword1 and keyword2
falsepositives:
    - Unknown
level: critical