Malicious Chrome Extension Sideload via --load-extension from User-Writable Path (via process_creation)

ATT&CK techniques

Persistence → Cred Access

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1176Software Extensions
Priv Esc
Defense Evasion
Cred Access
- T1539Steal Web Session Cookie
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a Chromium-based browser launched with the --load-extension flag pointing to a user-writable AppData or Public directory. The Ducktail campaign drops a malicious extension into the Chrome User Data folder and injects it through a LNK shortcut using --load-extension to steal session cookies and hijack business accounts, so this command line indicates unauthorized extension loading.

Reporting behind it

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Malicious Chrome Extension Sideload via --load-extension from User-Writable Path (via process_creation)

Pivot detection · T1539 · 9 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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