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.

The tech giants have evidence that Chinese hackers are exploiting the new bug, but warned "multiple actors" are also hacking into affected SharePoint systems.

Multiple hacking groups—including state actors from China—have targeted a vulnerability in older, on-premises versions of the file-sharing tool after a flawed attempt to patch it.