Ransomware has officially entered the Microsoft SharePoint exploitation ring. Late Wednesday, in an update to its earlier warning, Redmond confirmed that a threat group it tracks as Storm-2603 is abusing vulnerable on-premises SharePoint servers to deploy ransomware.

Threat actors exploit SharePoint flaws to access internal systems, steal sensitive data, and carry out surveillance, impersonation, and extortion.

Microsoft’s security analysts confirm that a number of cyber attacks on on-premise SharePoint Server users involve ransomware.