Pikabot Fake DLL Extension Execution Via Rundll32.EXE

title: Pikabot Fake DLL Extension Execution Via Rundll32.EXE
id: 1bf0ba65-9a39-42a2-9271-31d31bf2f0bf
status: test
description: |
    Detects specific process tree behavior linked to "rundll32" executions, wherein the associated DLL lacks a common ".dll" extension, often signaling potential Pikabot activity.
references:
    - https://github.com/pr0xylife/Pikabot
    - https://tria.ge/231004-tp8k6sch9t/behavioral2
    - https://www.virustotal.com/gui/file/56db0c4842a63234ab7fe2dda6eeb63aa7bb68f9a456985b519122f74dea37e2/behavior
    - https://tria.ge/231212-r1bpgaefar/behavioral2
author: Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
date: 2024-01-26
tags:
    - attack.execution
    - detection.emerging-threats
    - attack.stealth
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentImage|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\regsvr32.exe'
            - '\wscript.exe'
        Image|endswith: '\rundll32.exe'
        CommandLine|contains:
            - ':\ProgramData\'
            - ':\Users\Public\'
            - ':\Windows\Installer\'
            - '\AppData\Local\Temp\'
            - '\AppData\Roaming\'
    filter_main_known_extension:
        - CommandLine|contains:
              - '.cpl '
              - '.cpl,'
              - '.dll '
              - '.dll,'
              - '.inf '
              - '.inf,'
        - CommandLine|endswith:
              - '.cpl'
              - '.cpl"'
              - '.dll'
              - '.dll"'
              - '.inf'
              - '.inf"'
              - ".cpl'"
              - ".dll'"
              - ".inf'"
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high