**CEO URGENT: FBI Warns of Critical OneDrive Exploit Bypassing Outlook Security**
The FBI has issued a high-priority alert: a sophisticated phishing campaign is weaponizing Microsoft OneDrive to bypass standard Outlook security measures, targeting enterprise executives.
**The Vulnerability:** Attackers are sending emails from compromised, legitimate Outlook accounts. Instead of malicious attachments (which are often blocked), they share links to OneDrive folders containing weaponized HTML files. When opened, these files spoof Microsoft’s login page, capturing credentials and session cookies.
**Impact:** Full account takeover. Once inside, attackers escalate privileges, exfiltrate emails, and move laterally across the corporate network. One victim company lost $500K in wire fraud within 6 hours.
**CEO Action Required:**
1. **Immediate:** Force MFA re-authentication for all users.
2. **Policy:** Block external OneDrive sharing by default; allow only via explicit approval.
3. **Training:** All finance and executive staff must verify OneDrive requests verbally before opening.
Bottom line: The attack vector you pay to protect against (O365) is now the weapon. Patch your user behavior, not just the software.