huntrule

Windows Process Execution via Squirrel.exe Proxy Arguments

Identifies Windows executions of Squirrel.exe/Update.exe that use processStart-style arguments to launch other processes.

FreeReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems), Karneades / Markus Neis, Jonhnathan Ribeiro, oscd.community (SigmaHQ), DRL 1.1
Published
2022-06-09
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags Windows process creation events where the image path ends with \squirrel.exe or \update.exe and the command line contains Squirrel proxy arguments such as --processStart and related options. Attackers can abuse Squirrel’s process-start capabilities to launch arbitrary payloads through an application-native binary, helping blend execution into normal Electron app activity. The detection relies on process creation telemetry, specifically the Image path suffix and command-line argument substrings, with optional exclusions for known Electron updater shortcuts for Discord, GitHub Desktop, Teams, and Yammer.

Reporting behind it

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Windows Process Execution via Squirrel.exe Proxy Arguments
Pivot detection · T1218 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.