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

A China-linked threat actor has been observed exploiting SharePoint servers to deliver ransomware, according to Microsoft researchers, in the latest sign of worsening attacks against on-premises SharePoint Server customers.

Microsoft Corp. said a Chinese hacking group is exploiting security vulnerabilities in the company’s SharePoint servers to deploy ransomware, following a cyberattack discovered last week that has affected hundreds of entities around the world.