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 News reported on Friday.

Microsoft identified three China-based hacking groups targeting SharePoint vulnerabilities in the ongoing cyberattack, and urged customers to ensure they've applied security updates.

Microsoft confirms Chinese hackers exploited a SharePoint flaw; Patches now available. Cloud-based Microsoft 365 not affected.

A series of cyberattacks targeting Microsoft collaboration software, specifically SharePoint, have been linked to Chinese hackers and threat actors.