blue-team-tools/rules/windows/powershell/powershell_suspicious_invocation_specific.yml

title: Suspicious PowerShell Invocations - Specific
id: fce5f582-cc00-41e1-941a-c6fabf0fdb8c
status: experimental
description: Detects suspicious PowerShell invocation command parameters
tags:
    - attack.execution
    - attack.t1059.001
    - attack.t1086  #an old one
author: Florian Roth (rule), Jonhnathan Ribeiro
date: 2017/03/05
logsource:
    product: windows
    service: powershell
detection:
    convert_b64:
        Message|contains|all:
            - '-nop'
            - ' -w ' 
            - 'hidden' 
            - ' -c '
            - '[Convert]::FromBase64String'
    iex_selection:
        Message|contains|all:
            - ' -w ' 
            - 'hidden'
            - '-noni'
            - '-nop' 
            - ' -c '
            - 'iex'
            - 'New-Object'
    enc_selection:
        Message|contains|all:
            - ' -w ' 
            - 'hidden'
            - '-ep'
            - 'bypass'
            - '-Enc'
    reg_selection:
        Message|contains|all:
            - 'powershell' 
            - 'reg'
            - 'add'
            - 'HKCU\software\microsoft\windows\currentversion\run'
    webclient_selection:
        Message|contains|all:
            - 'bypass' 
            - '-noprofile'
            - '-windowstyle'
            - 'hidden'
            - 'new-object'
            - 'system.net.webclient'
            - '.download'
    iex_webclient:
        Message|contains|all:
            - 'iex'
            - 'New-Object'
            - 'Net.WebClient'
            - '.Download'
    condition: 1 of them
falsepositives:
    - Penetration tests
level: high