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.

Among the attackers now actively exploiting vulnerable on-premises Microsoft SharePoint servers, at least one has shown indications of originating from China, according to the assessment of researchers at Google Cloud-owned Mandiant.

A major cyberattack has hit Microsoft's SharePoint platforms, putting thousands of organizations at risk around the world. The attack began