Potential Goopdate.DLL Sideloading — Sigma Rule

Rule metadata and linked tags

Author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-05-15 / 2025-10-07.

{
  "category": "image_load",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 8ce09cdb41b1b705c1953cb44f684674707b64f8a1b5e6d9af0e838ecaa14177

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential Goopdate.DLL Sideloading
id: b6188d2f-b3c4-4d2c-a17d-9706e0851af0
status: test
description: Detects potential DLL sideloading of "goopdate.dll", a DLL used by googleupdate.exe
references:
    - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf
author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-15
modified: 2025-10-07
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\goopdate.dll'
    filter_main_generic:
        ImageLoaded|startswith:
            # Many third party chromium based apps use this DLLs. It's better to create a baseline and add specific filters
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
    filter_optional_dropbox_installer_temp:
        Image|contains|all:
            - '\AppData\Local\Temp\GUM'
            - '.tmp\Dropbox'
        ImageLoaded|contains|all:
            - '\AppData\Local\Temp\GUM'
            - '.tmp\goopdate.dll'
    filter_optional_googleupdate_temp:
        Image|contains:
            - '\AppData\Local\Temp\GUM'
            - ':\Windows\SystemTemp\GUM'
        Image|endswith: '.tmp\GoogleUpdate.exe'
        ImageLoaded|contains:
            - '\AppData\Local\Temp\GUM'
            - ':\Windows\SystemTemp\GUM'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - False positives are expected from Google Chrome installations running from user locations (AppData) and other custom locations. Apply additional filters accordingly.
    - Other third party chromium browsers located in AppData
level: medium

Original YAML and metadata in JSON

False positives

• False positives are expected from Google Chrome installations running from user locations (AppData) and other custom locations. Apply additional filters accordingly.
• Other third party chromium browsers located in AppData

Source references

• https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf