One of the hacked organizations reportedly includes the U.S. agency responsible for maintaining the country's stockpile of nuclear weapons. China-backed hackers have been observed carrying out the hacks targeting SharePoint servers.

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

Victims of the recent global hacking campaign include the National Institutes of Health and the National Nuclear Security Administration, officials said.

Hours after Microsoft revealed hacking groups affiliated with the Chinese government have been exploiting a flaw in its SharePoint software, Bloomberg News reports that the National Nuclear Security Administration has also been breached in the attacks.

A sweeping cyber espionage operation targeting Microsoft server software compromised about 100 organizations as of the weekend, two of the organizations that helped uncover the campaign said.