Police in central China have shut down a hacker training operation that openly recruited thousands of members online and provided them with cyberattack lessons and malicious software, state media said on Monday.

Hackers may target popular new devices with a rapidly growing user base like smartphones and Microsoft's operating system Windows 7 next year, a study said.

Microsoft said on Thursday that cybercriminals are already hawking booby-trapped versions of just-released Windows 7 operating system software.

China denied media reports that hackers in the country breached a US jet fighter program two years ago, calling the allegations on Thursday "irresponsible" and "made up."

A Chinese cyber spy network has hacked into nearly 1,300 computers across 103 countries, with India being the fourth-worst victim, and the infected machines include those at Indian embassies and other government organisations.