**SUBJECT: FBI CYBER ALERT: Outlook / OneDrive Under Active, Stealth Attack**
**MANDATORY EXECUTIVE READ**
**The FBI and CISA have issued an urgent, joint flash alert.** Nation-state actors are actively exploiting three newly discovered critical vulnerabilities in Microsoft 365.
**The Target:** Your company’s email and cloud file storage—specifically Outlook and OneDrive. This is not a phishing test. This is a confirmed, in-progress data exfiltration campaign.
**The Attack Vector:** Microsoft Office suite “zero-click” exploits that bypass multi-factor authentication. The attacker requires zero user interaction to gain full read/write access.
**The Business Impact:**
1. **Total Email Harvesting:** All internal and external communications are compromised.
2. **Data Extortion:** Attackers are deleting or encrypting OneDrive files immediately post-access.
3. **Supply Chain Contamination:** Compromised accounts are being used to send malicious emails *from legitimate domains* to your partners.
**Immediate Required Action by Your IT Team (Within 4 Hours):**
1. **Revoke All OAuth Tokens** for Outlook and OneDrive (Step-by-step in the attached PDF).
2. **Enable Strict Email Archiving** to preserve evidence for forensic analysis.
3. **Disable Legacy Authentication Protocols** immediately.
**Final Assessment:** If your organization uses Outlook or OneDrive, you should assume compromise. This is the digital equivalent of a fire alarm in a fuel depot—act now, not after the audit.
**Source:** FBI Flash Alert AA24-XXXA released [Current Date].