ConnectWise Cloud Backup Service Halted After Microsoft 365 Tenant Compromise

ConnectWise has suspended its Cloud Backup service and disabled seven application identities after a security incident. Attackers compromised 173 Microsoft 365 environments by hijacking the application's identity, allowing unauthorized sign-ins without passwords or multi-factor authentication. The incident, identified on October 14, 2026, highlights significant cybersecurity vulnerabilities in cloud service integrations.