Microsoft 365: New Trust Center settings to block file opens using insecure protocols

🚨 The Signal: New Trust Center settings allow blocking file opens via insecure FTP/HTTP and FPRPC protocols. This enhances protection against malicious content delivered through legacy, unencrypted channels, reducing attack surface.

The Impact

All users are affected by reduced risk from insecure file access protocols, enhancing overall security posture.

• End users: May be blocked from opening files from insecure sources.
• Security teams: Gain granular control over insecure protocol usage.
• Admins: Need to configure and communicate new security policies.
• Organisations: Reduced risk of malware via legacy protocols.

The Action

1. Review current usage of FTP/HTTP/FPRPC for file access within your organisation.
2. Access Microsoft 365 Trust Center settings for M365 Apps.
3. Configure policies to restrict or block file opens using insecure protocols (FTP/HTTP/FPRPC).
4. Communicate changes to end-users regarding secure file access methods.
5. Monitor security logs for blocked access attempts to identify legacy dependencies.

Domain: M365-Apps · Impact: high · Workload: M365 Apps · Essential Eight: User Application Hardening · ISM: ISM-1412, ISM-1485, ISM-1486, ISM-1542, ISM-1585, ISM-1667, ISM-1668, ISM-1669, ISM-1670, ISM-1823, ISM-1824, ISM-1859, ISM-1860