title: PowerShell ShellCode
id: 16b37b70-6fcf-4814-a092-c36bd3aafcbd
status: experimental
description: Detects Base64 encoded Shellcode
references:
    - https://twitter.com/cyb3rops/status/1063072865992523776
tags:
    - attack.defense_evasion
    - attack.privilege_escalation
    - attack.t1055
    - attack.execution
    - attack.t1059.001
    - attack.t1086  #an old one
author: David Ledbetter (shellcode), Florian Roth (rule)
date: 2018/11/17
modified: 2020/12/01
logsource:
    product: windows
    service: powershell
    definition: 'Script block logging must be enabled'
detection:
    selection:
        EventID: 4104
        ScriptBlockText|contains: 'AAAAYInlM'
    selection2:
        ScriptBlockText|contains:
            - 'OiCAAAAYInlM'
            - 'OiJAAAAYInlM'
    condition: selection and selection2
falsepositives:
    - Unknown
level: critical