Suspicious Browser Extension Sideload From a User Path (via process_creation)

ATT&CK techniques

Persistence

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1176Software Extensions
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a Chromium-based browser launched with --load-extension pointing at an extension in AppData, Temp or ProgramData, the persistence behavior ChromeLoader uses to inject a malicious browser extension. Loading an unpacked extension from a user-writable path is a technique tracked in the Red Canary Threat Detection Report. Detecting this invocation surfaces browser hijacking for adware or credential theft.

Reporting behind it

Related detections8 linkedT1176 — drag to rearrange

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Windows: Chromium-Based Browser Launched via Script Host with --load-extension

Windows Chromium-Based Browser Launched With --load-extension Flag

Windows ChromeLoader Execution via Scheduled Task and Hidden PowerShell Launch

Suspicious Browser Extension Sideload From a User Path (via process_creation)

Pivot detection · T1176 · 8 related

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

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