The four Chinese cyber-criminals behind the Fujacks worm have been jailed by a Chinese court.

Fujacks caused havoc earlier this year when it covertly stole usernames and passwords from online gamers, and converted icons of infected programs into a picture of a panda burning joss-sticks.

Li Jun, who confessed to writing the worm and selling it to 12 clients for more than ¥100,000 yuan (£6,250) was sentenced to four years in prison by a court in Xiantao in Hubei province.

Wang Lei, Zhang Shun and Lei Lei were sentenced to between one year and two and a half years in jail for their part in the scheme.

"Chinese cyber-criminals are not just hitting PCs in their own country, but affecting computer users worldwide, so it is encouraging to see the authorities taking action against the perpetrators," said Graham Cluley, senior technology consultant at Sophos.

"A surprising proportion of malware written in China is designed to steal credentials from players of massively multi-player online role-playing games."

Chinese authorities said that the majority of the Fujacks infections have been dealt with after police persuaded Li Jun to write a counter-agent to his program to clean-up infected computers.

"Despite the worm's author writing a program to clean up his infestation, it does not seem to have gained him much sympathy from the authorities," noted Cluley.

Chinese hackers have been making the headlines recently. Online attacks on governments in the US, UK and Germany have been blamed on Chinese hackers working for the Chinese People's Liberation Army (PLA), a claim that China has strongly denied.