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

Microsoft Corp. has determined that China-linked hacking groups are targeting deployments of its SharePoint file sharing platform. The company detailed its findings in a blog post published today.

Microsoft issued an emergency fix to close off a vulnerability in its SharePoint software that hackers have exploited to carry out widespread attacks on businesses and at least some federal agencies.

Researchers first uncovered a sweeping cyber espionage operation targeting Microsoft server software affecting at least 100 organisations.

Microsoft Corp.’s server software is under attack from unidentified hackers, with cybersecurity analysts warning of widespread security breaches across the globe.The Redmond, Washington-based software maker said it had released a new security patch for customers to apply to their SharePoint servers “to mitigate active attacks targeting on-premises servers,