Hackers sponsored by the Chinese state have breached a number of U.S. government institutions, including the agency responsible for overseeing the security of America’s nuclear arsenal, Microsoft warned.

The Chinese government has warned against using cyber security issues to defame the country, following the hacker attacks on Microsoft software. Foreign Ministry spokesman Guo Jiakun said in Beijing on Wednesday that he was not aware of the exact circumstances of the attacks.

In ongoing hacks, Microsoft says it has identified two Chinese hacking groups taking advantage of a key software flaw.

Chinese "threat actors" have hacked Microsoft's SharePoint document software servers and targeted the data of the businesses using it, the firm has said.

After a ProPublica investigation raised security concerns, Microsoft will cease using China-based engineers for work on sensitive Pentagon cloud computing systems.

Some of the most sensitive data the United States has to offer is currently being maintained by engineers from China, often considered, especially in the tech field, its biggest adversary.

The move comes after a ProPublica report highlighted a Microsoft program that allows foreign engineers to indirectly interact with U.S. military systems through American “escort” intermediaries.

Defense Secretary Pete Hegseth says the DOD is "looking into" a Microsoft cloud program that used Chinese engineers after an investigative report raised concerns about CCP access.