China has hit back at reports that Chinese hackers spied on US critical infrastructure, calling it a disinformation campaign waged by Washington and its allies.

"Relevant reports from Western agencies have no proof," said Foreign Ministry spokeswoman Mao Ning at a regular press briefing on Thursday.

"This is an extremely unprofessional report with a missing chain of evidence, this is just scissors-and-paste work," Mao said, adding that the allegations were "a collective disinformation campaign of the Five Eyes coalition countries".

The US, its allies and Microsoft said on Wednesday state-sponsored Chinese hackers have infiltrated critical US infrastructure networks, and similar espionage attacks could be occurring globally. Microsoft said the targets include sites in the US Pacific territory of Guam, where Washington has a major military presence. (Agencies)