A cyber-espionage campaign centered on vulnerable versions of Microsoft's server software now involves the deployment of ransomware, Microsoft said in a late Wednesday blog post.

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

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.