Compromised ConnectWise Credential Used to Access 173 Microsoft 365 Environments in Supply Chain Attack
A compromised credential from ConnectWise Cloud Backup, formerly known as SkyKick Backup, was abused to access at least 173 partner and customer Microsoft 365 environments. Microsoft Threat Intelligence classified the incident as an active supply chain attack. The attacker bypassed password and multi-factor authentication by using a client assertion issued from the vendor environment, impersonating an already-approved application identity to obtain Microsoft Graph tokens. Access occurred on October 15 between 06:13 and 08:34 UTC, with the intruder enumerating environment identifiers sequentially at short intervals, indicating automated scripting against a prepared target list. The backup application's permissions covered Exchange, OneDrive, SharePoint, Teams, and directory information. In one environment, another vendor application was granted global administrator rights and planted secrets in two trusted applications valid until 2028. ConnectWise later disabled seven application identities, revoked affected certificates, and suspended Cloud Backup services.
BoletimSecOct 19, 2026Translated from Portuguese
