Potential Pikabot Hollowing Activity

title: Potential Pikabot Hollowing Activity
id: d8937fe7-42d5-4b4d-8178-e089c908f63f
status: test
description: |
    Detects the execution of rundll32 that leads to the invocation of legitimate Windows binaries.
    The malware Pikabot has been seen to use this technique for process hollowing through hard-coded Windows binaries
references:
    - https://www.virustotal.com/gui/file/b6e8910fb9b3bb1fcddefd35ff0ed8624930d30d6977e11808c8330415685a62
    - https://www.virustotal.com/gui/file/6bb4cdbaef03b732a93559a58173e7f16b29bfb159a1065fae9185000ff23b4b
    - https://github.com/pr0xylife/Pikabot/blob/7f7723a74ca325ec54c6e61e076acce9a4b20538/Pikabot_06.12.2023.txt
author: Andreas Braathen (mnemonic.io)
date: 2023-10-27
modified: 2024-01-26
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055.012
    - detection.emerging-threats
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentImage|endswith: '\rundll32.exe'
        Image|endswith:
            # Note: Only add processes seen used by Pikabot to avoid collision with other strains of malware
            - '\SearchFilterHost.exe'
            - '\SearchProtocolHost.exe'
            - '\sndvol.exe'
            - '\wermgr.exe'
            - '\wwahost.exe'
    filter_main_legit_sndvol:
        Image|endswith: '\sndvol.exe'
        ParentCommandLine|contains: 'mmsys.cpl'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high