The number of companies and organizations compromised by a security vulnerability in Microsoft Corp.’s SharePoint servers is increasing rapidly, with the tally of victims soaring more than six-fold in a few days,

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

US tech giant Microsoft has pointed the finger at China amid a wave of cyberattacks on firms and government agencies worldwide, announcing on Tuesday that it has identified three Chinese hacker groups responsible for the damage so far.