Suspicious Chromium Browser Instance Executed With Custom Extension (via process_creation)

title: Suspicious Chromium Browser Instance Executed With Custom Extension (via process_creation)
id: 5dfb01b1-a9f9-571c-bb41-af090a4b837d
status: stable
description: This rule detects a Chromium based browser process with the 'load-extension' flag to start a instance with a custom extension
references:
    - https://attack.mitre.org/techniques/T1176/001/
    - https://redcanary.com/blog/chromeloader/
    - https://emkc.org/s/RJjuLa
    - https://www.mandiant.com/resources/blog/lnk-between-browsers
author: Huntrule Team
date: 2026-02-08
tags:
    - attack.persistence
    - attack.t1176.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\brave.exe'
            - '\chrome.exe'
            - '\msedge.exe'
            - '\opera.exe'
            - '\vivaldi.exe'
        CommandLine|contains: '--load-extension='
    condition: selection
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_browsers_chromium_load_extension/info.yml