ConnectWise Cloud Backup Breach Affects 173 Microsoft 365 Tenants via API Credential Compromise

ConnectWise has disclosed a security incident impacting 173 customer tenants, where attackers compromised a Microsoft 365 API credential for its Cloud Backup application. This allowed unauthorized access to customer tenants without requiring passwords or multi-factor authentication, as the sign-ins were authenticated as the application itself. ConnectWise has disabled affected application identities and suspended the Cloud Backup service while investigations and remediation efforts are ongoing.