Microsoft is investigating whether a leak from its early alert system for cybersecurity companies allowed Chinese hackers to exploit flaws in its SharePoint service before they were patched, Bloomberg...

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.

A security patch Microsoft released this month failed to fully fix a critical flaw in the U.S. tech giant's SharePoint server software, opening the door to a sweeping global cyber espionage effort.