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

In what’s one of the more significant series of cyberattacks in 2025, hackers are targeting a severe weakness in Microsoft’s Sharepoint software, which is used by its customers to build and manage shared files. Among the attackers, according to Google security researchers, is a Chinese-affiliated group.

Microsoft is investigating a potential leak within its MAPP program, suspecting that Chinese state-backed hackers exploited SharePoint vulnerabilities