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

Researchers say Chinese actors, along with other criminal hackers, exploited a security flaw in SharePoint software widely used by governments and businesses.

Suspected Chinese hackers have broken into the email accounts of attorneys and advisers at a powerful Washington, DC, law firm in an apparent intelligence-gathering operation, the firm, Wiley Rein, told clients this week in a memo reviewed by CNN.

Hackers in recent weeks have exploited flaws in SharePoint, a document management system developed by Microsoft Corp., to try to steal sensitive data from hundreds of victims.