Suspicious Arbitrary File Download Through Squirrel.EXE (via process_creation)

title: Suspicious Arbitrary File Download Through Squirrel.EXE (via process_creation)
id: b0021a0d-609d-5566-81bc-f94fbaf45a89
status: stable
description: This rule detects the use of the "Squirrel.exe" to download arbitrary files. This binary is part of multiple Electron based software installations (Slack, Teams, Discord, etc.)
references:
    - https://attack.mitre.org/techniques/T1218/
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Squirrel/
    - http://www.hexacorn.com/blog/2019/03/30/sqirrel-packages-manager-as-a-lolbin-a-k-a-many-electron-apps-are-lolbins-by-default/
    - http://www.hexacorn.com/blog/2018/08/16/squirrel-as-a-lolbin/
author: Huntrule Team
date: 2026-01-24
tags:
    - attack.execution
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith:
            - '\squirrel.exe'
            - '\update.exe'
    selection_download_cli:
        CommandLine|contains:
            - ' --download '
            - ' --update '
            - ' --updateRollback='
    selection_download_http_keyword:
        CommandLine|contains: 'http'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium