CTI · corroborated · 2026-08-20

Hackers Create Hidden Microsoft 365 Inbox Rules to Conceal Vendor Payment Fraud

Full story & timeline

MITRE ATT&CK

• T1557 Adversary-in-the-Middle Credential Access
• T1539 Steal Web Session Cookie Credential Access
• T1564 Hide Artifacts Stealth
• T1657 Financial Theft Impact

Indicators

No curated indicators tied to this case.

Detections

No detection content yet — case analysis did not yield signal-specific telemetry. Check back after the next daily CTI pass.

References

• https://www.gbhackers.com/hackers-create-hidden-microsoft-365-inbox-rules/