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.

Researchers say Chinese actors, along with other criminal hackers, exploited a security flaw in SharePoint software widely used by governments and businesses.

Microsoft has warned that Chinese state-sponsored hackers have breached its SharePoint software used by the US agency responsible for maintaining and modernizing the nation’s stockpile of nuclear weapons, according to a report.

A China-linked threat actor has been observed exploiting SharePoint servers to deliver ransomware, according to Microsoft researchers, in the latest sign of worsening attacks against on-premises SharePoint Server customers.

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

US President Donald Trump urged tech giants to halt overseas hiring, emphasising job creation at home during an AI Summit. He criticised companies like Google and Microsoft for outsourcing and unveiled new executive orders aimed at reshaping AI infrastructure.

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.

Following a Pro Publica report that Microsoft was using engineers in China to help maintain cloud computing systems for the U.S. Department of Defense, the company said it’s made changes to ensure this will no longer happen.

The change follows a ProPublica report that outlined how Microsoft’s use of Chinese engineers left U.S. defense clients vulnerable to cybersecurity risks.