title: Regsvr32 Anomaly
status: experimental
description: Detects various anomalies in relation to regsvr32.exe
author: Florian Roth
references:
    - https://subt0x10.blogspot.de/2017/04/bypass-application-whitelisting-script.html
tags:
    - attack.t1117
    - attack.defense_evasion
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection1:
        Image: '*\regsvr32.exe'
        CommandLine: '*\Temp\\*'
    selection2:
        Image: '*\regsvr32.exe'
        ParentImage: '*\powershell.exe'
    selection3:
        Image: '*\regsvr32.exe'
        CommandLine:
            - '*/i:http* scrobj.dll'
            - '*/i:ftp* scrobj.dll'
    selection4:
        Image: '*\wscript.exe'
        ParentImage: '*\regsvr32.exe'
    selection5:
        Image: '*\EXCEL.EXE'
        CommandLine: '*..\..\..\Windows\System32\regsvr32.exe *'
    condition: 1 of them
fields:
    - CommandLine
    - ParentCommandLine
falsepositives:
    - Unknown
level: high