A blacklisted Chinese company claims to have developed a “cyber nuclear weapon” that could be used to hack Western companies and governments.

Zhou Hongyi, the chief executive of cybersecurity company Qihoo 360, said it had built an AI system that matched the capabilities of Anthropic’s Claude Mythos, the most powerful US AI technology.

It comes after Five Eyes nations warned that enemies were just months away from being able to carry out devastating cyber attacks.

Qihoo has been blacklisted by the US government since 2020 over claims that it is linked to the Chinese military. Earlier this month, the Pentagon accused Qihoo of being a “military civil fusion contributor to the Chinese defence industrial base” tied to Beijing’s intelligence agencies.

The Chinese business previously said it rejected the accusations.

Mr Zhou’s claims about Qihoo’s technology have not been verified, but experts say China will eventually be able to develop AI that can carry out sophisticated hacks.

Mythos, unveiled by Anthropic in April, was described as “reshaping cybersecurity” because of its ability to uncover thousands of previously unknown bugs in software and exploit them.

Anthropic initially withheld Mythos from the public over concerns it was too dangerous to release. It later offered it to a handful of business customers, while the National Security Agency, the US equivalent of GCHQ, trialled the AI to find flaws in classified government systems.

However, Anthropic was forced to withdraw the AI entirely after the White House imposed export controls on the technology over fears hackers could bypass its safeguards and carry out attacks.

Mr Zhou, speaking at an internet security conference in China, said that Mythos was the “equivalent to a cyber nuclear weapon in the AI era” and a “strategic asset” to the US.

He said that Qihoo had developed its own system, called Tulongfeng, which he billed as a “Chinese version of Mythos, possessing similar vulnerability discovery capabilities”.

While not as powerful as Mythos, he said it could be paired with Qihoo’s other technologies resulting in a hacking tool equivalent to Anthropic’s system.

He compared the development of AI cyber systems to the nuclear arms race. “Previously, nuclear weapons constituted strategic deterrence. In the future, vulnerability discovery capabilities may become the new strategic deterrent,” Mr Zhou said.

“China’s cybersecurity industry must possess its own Mythos. This game-changing weapon of mass destruction cannot remain solely in the hands of others.”

He said Tulongfeng had discovered more than 3,000 vulnerabilities, several of which were deemed “high risk” by Chinese officials.

The cyber chiefs of the Five Eyes nations – the US, the UK, Canada, New Zealand and Australia – warned earlier this week that adversaries would soon be able to use AI to develop overwhelming attacks.

“The timeline is not years, it is months,” the joint warning said.

Alan Woodward, a cyber security expert at the University of Surrey, said it was inevitable that China would develop such systems. “It might not be as good as Mythos, but what it does show is these things are going to come out anyway,” he said.

AI labs have also accused China of attempting to copy American chatbot systems, using so-called “distillation attacks” to leapfrog Silicon Valley in the AI race.

Anthropic accused Chinese tech giant Alibaba earlier this month of trying to syphon off its AI technology to improve its own chatbots.

In a letter to Congress, Anthropic claimed Alibaba had “brazenly” sent millions of queries to its Claude bot in an attempt to reverse engineer the AI tool.