Sigma rule: Arbitrary File Download Via Squirrel.EXE

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-a197f4dfc674, updated 2023-11-09T00:00:00.000Z.

Rule

Title: Arbitrary File Download Via Squirrel.EXE
Status: test
Level: medium
Author: Nasreddine Bencherchali (Nextron Systems), Karneades / Markus Neis, Jonhnathan Ribeiro, oscd.community
Date: 2022-06-09
Modified: 2023-11-09
File: rules/windows/process_creation/proc_creation_win_squirrel_download.yml
Commit: ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the usage of the "Squirrel.exe" to download arbitrary files. This binary is part of multiple Electron based software installations (Slack, Teams, Discord, etc.)

Log source

product: windows
category: process_creation

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_*

False positives (as the rule lists them)

Expected FP with some Electron based applications such as (1Clipboard, Beaker Browser, Caret, Discord, GitHub Desktop, etc.)

MITRE ATT&CK ids this rule names

T1218

Related rules

References

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/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_squirrel_download.yml

Sources and licences

SigmaHQ
"Arbitrary File Download Via Squirrel.EXE" by Nasreddine Bencherchali (Nextron Systems), Karneades / Markus Neis, Jonhnathan Ribeiro, oscd.community (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_squirrel_download.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License
Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Arbitrary File Download Via Squirrel.EXE",
entity page, dataset version ref-a197f4dfc674, updated 2023-11-09T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/1e75c1cc-c5d4-42aa-ac3d-91b0b68b3b4c (accessed 2026-11-03).
Underlying source: SigmaHQ rule 1e75c1cc-c5d4-42aa-ac3d-91b0b68b3b4c, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.