Mike McConnell, who served as director of national intelligence under President George W Bush, made the comments during a speech at the University of Missouri.
"The Chinese have penetrated every major corporation of any consequence in the United States and taken information," he said.
"We've never, ever not found Chinese malware," he said on Thursday.
In his speech, McConnell also said that during the final years of the Bush administration, the Chinese government employed a jaw-dropping 100,000 hackers dedicated solely to breaking into computers. By comparison, he said the United States had that many spies -- total.
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He listed victims he has come across during his investigations: US Congress, Department of Defense, State Department and major corporations.
The US government has said it has caught Chinese spies stealing blueprints and business plans. Last year, federal prosecutors took the unprecedented step of filing formal criminal charges against five Chinese government spies for breaking into Alcoa, US Steel Corp., Westinghouse and others.
But McConnell's assertion is different. It would mean that no large company can escape the massive theft of American entrepreneurial ideas, CNN Money reported.
"If they can take that, before we can take it to market - for free - and it's unchecked for 15, 20 years, I would say that has strategic consequences for the United States," he said.
Several hacking experts who consult companies on cybersecurity backed up the idea that Chinese hacking is widespread. But they doubt every, single major US company has been broken into by Chinese government operatives.
Others doubted McConnell's assertions, noting that placing the blame after a hack is extremely difficult.
McConnell did not respond to calls for comment on Friday, the report said.