“This is an extremely unprofessional report with a missing chain of evidence, this is just scissors-and-paste work,” foreign ministry spokesman Mao Ning said.

The allegations were “a collective disinformation campaign of the Five Eyes coalition countries”, she said.

In a report Wednesday, Microsoft highlighted Guam, a US territory in the Pacific Ocean with a vital military outpost, as one of the targets of the alleged Chinese state-backed hackers.

But, it said, “malicious” activity had also been detected elsewhere in the US.

The stealthy attack – carried out by a China-sponsored actor dubbed “Volt Typhoon” since mid-2021 – enabled long-term espionage and was likely aimed at hampering the US in the event of a conflict, it said.

The claims were echoed by the US and its allies in the Five Eyes security alliance – Australia, Canada, New Zealand and the United Kingdom – accusations Beijing denied today.

The US, Mao said, “was expanding new channels for disseminating disinformation”.

“But no change in tactics can alter the fact that the US is a hacker empire,” she said.