Kapeka Backdoor Execution Via RunDLL32.EXE

Detects Kapeka backdoor process execution pattern, where the dropper launch the backdoor binary by calling rundll32 and passing the backdoor's first export ordinal (#1) with a "-d" argument.

title: Kapeka Backdoor Execution Via RunDLL32.EXE
id: e98f741c-6a5b-4c83-bc2a-1f4e58d07b12
status: test
description: |
    Detects Kapeka backdoor process execution pattern, where the dropper launch the backdoor binary by calling rundll32 and passing the backdoor's first export ordinal (#1) with a "-d" argument.
references:
    - https://labs.withsecure.com/publications/kapeka
    - https://app.any.run/tasks/1efb3ed4-cc0f-4690-a0ed-24516809bc72/
author: Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
date: 2024-07-03
tags:
    - attack.stealth
    - attack.t1218.011
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\rundll32.exe'
        - OriginalFileName: 'RUNDLL32.EXE'
    selection_backdoor_path:
        CommandLine|contains:
            - ':\ProgramData'
            - '\AppData\Local'
    selection_backdoor_exec_1:
        CommandLine|contains|all:
            - '.wll'
            - '#1'
            - ' -d'
    selection_backdoor_exec_2:
        # This account for the in the wild variant
        CommandLine|contains: '.wll'
        CommandLine|endswith: '#1'
    condition: selection_img and selection_backdoor_path and 1 of selection_backdoor_exec_*
falsepositives:
    - Unknown
level: high

• T1218.011Rundll32

• https://labs.withsecure.com/publications/kapeka↗
• https://app.any.run/tasks/1efb3ed4-cc0f-4690-a0ed-24516809bc72/↗