Chinese hackers are back in action -

The Chinese hackers who went quiet after the US made a big noise about their operations, appear to be back in business again.

Earlier this year, the US moaned about a secretive Chinese military unit believed to be behind a series of hacking attacks.

Shanghai-based Unit 61398 was named and shamed for a large number of US attacks, although China's Defence Ministry denied the claims. However the attacks stopped.

Now it seems that with the US being outted as the country with a serious cyber spying problem, the Chinese are back.

The US-China Economic and Security Commission, a panel which advises the US Congress on China policy, said Mandiant's revelations brought a brief pause in cyber intrusions by that PLA unit.

The commission said in a draft of its annual report to Congress that there was no indications the public exposure of Chinese cyber espionage in technical detail throughout 2013 has led China to change its attitude toward the use of cyber espionage to steal economic and trade information.

According to Reuters, Mandiant's revelations "merely led Unit 61398 to make changes to its cyber 'tools and infrastructure' to make future intrusions harder to detect and attribute."

The Chinese embassy in Washington said that the cyber attacks are transnational and anonymous and no one knows how the evidence against China is collected.

It is fairly likely that the unit re-activated with new tools and methods after it was revealed by former US National Security Agency contractor Edward Snowden's that the US NSA had conducted cyber-operations against targets in China and Hong Kong.