Suspicious Firefox Enterprise Root Certificate Trust Enabled

ATT&CK techniques

Defense Evasion → Collection

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1553.004Install Root Certificate
Cred Access
- T1557Adversary-in-the-Middle
Discovery
Lateral Movement
Collection
- T1557Adversary-in-the-Middle
C2
Exfiltration
Impact

What it detects

This rule detects the Firefox preference security.enterprise_roots.enabled being set to true, forcing Firefox to trust certificates from the Windows root store. Microsoft observed Secret Blizzard enabling this so their rogue root certificate would be trusted by Firefox for AiTM interception. Because Firefox normally maintains its own trust store, this change extends the attacker root into the browser and enables traffic decryption.

Reporting behind it

Related detections9 linkedT1557 — drag to rearrange

Malicious Root Certificate Installed via certutil addstore for AiTM Interception

Suspicious Code of Conduct Phishing Email From cocinternal.com Sender (via m365)

Suspicious Entra Sign-In With Axios Automation User-Agent via AiTM Token Replay (via azure)

Malicious Root Certificate Installation via certutil

Suspicious Root Certificate Installation via certutil (via process_creation)

Suspicious Tycoon Phishing-as-a-Service Credential Exfiltration Path (via proxy)

Suspicious OfficeHome Sign-In With Axios User Agent via Tycoon 2FA Proxy

Suspicious AWS AiTM Phishing Kit Endpoint Access via Proxy

Possible AiTM Phishing Sign-On Evaluation Denied by Okta FastPass

Suspicious Firefox Enterprise Root Certificate Trust Enabled

Pivot detection · T1557 · 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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