"I didn't expect it to cause so much damage," Li Jun told a court in the central province of Hubei. "I apologize to all the victims of the virus and internet users nationwide."

Li Jun, 25, and three others all in their 20s, stand accused of writing the notorious computer virus "Xiongmao Shaoxiang," or "Panda burning joss stick," spreading it through the Internet and causing huge damage to millions of computer users from November 2006 to March 2007.

The trial began in the People's Court of Xiantao City, in Hubei Province. Li Jun, creator of the virus, made 145,000 yuan from selling anti-virus software to combat the virus and was jailed for four years, and his three accomplices were jailed for up to two and a half years each.

Police say the four defendants made more than 200,000 yuan from selling the virus, which infects program files and flashes up an image of a panda holding three joss sticks and can also steal the account names and passwords of online game players and popular chat sites. It was listed as the worst computer virus last year by China's leading anti-virus company Rising.

After the trial, Western security researchers also hailed the punishment as fair. "Chinese cyber criminals are not just hitting PCs in their own country, but impacting computer users worldwide, so it's encouraging to see the authorities taking action," said Graham Cluley, a Sophos PLC's senior technology consultant.

However, Zhang Zhaowang, the father of one of the accomplices, Zhang Shun, said he was considering appealing to a higher court as he thought his son didn't deserve such a heavy punishment.

The virus business

In March, when Li Jun was arrested, Zhang Lianyao, an official at the Internet monitoring division of Xiantao Public Security Bureau, said that the virus industry chain involves several links and each with different ways of making money.

In the Panda virus case, Li wrote the virus at the request of a buyer. The virus made infected computers go to a certain website, where the virus buyer attached a Trojan horse virus capable of invading the computer and stealing information, which was then sent to a "receiver" via email. The "receiver" then sold the information to an "envelope opener," who finally sold the information online.

According to Shi Yu, an anti-virus engineer at the Beijing-based Rising, virus makers have two main ways to make money. One is to directly sell their virus on the request of a buyer. The other way is to sell the "naked chicken," a nickname for computers that are infected with viruses and are controlled by the virus maker. Information contained in these "naked chickens" can be stolen at any time.

Use the talents properly

The latest computer virus report from Rising shows that a total of 133,717 new viruses affected the Chinese mainland in the first half of 2007. With an estimated 162 million netizens at the end of June, China is in urgent need of legislation on cyber crime, experts say. The country's booming Internet industry is filled with technology-savvy youngsters, who sometimes cause or are the victims of problems including addiction, hacking, and virtual property theft.

Before Li Jun was arrested, he was estimated to have made around 100,000 yuan in one year from Trojan horse viruses he wrote for The Legend of Mir, a massive online role-playing game, according to one of his old friends surnamed Zhong.

"Li Jun is a product of the times," Zhong said. "Had it not been Li Jun, there would have been others like him."

"It is a small investment but a highly lucrative crime," warned Shi Yu, an anti-virus engineer at Rising.

During the trial of the four cyber criminals there was some good news for Li. His defense lawyer Wang Wanxiong presented an invitation letter from an Internet company in Hangzhou, capital of east China's Zhejiang Province. The company said in the letter that it wanted to hire Li Jun as the technology director.

"We wanted to offer him a legal job to cultivate a favorable environment for him to use his talents," said Dong Zhenguo, the company's manager, adding that he had learnt via the media that Li was not a bad man but just went astray.

According to Wang, there are more than 10 companies hoping to hire Li, with as much as 1 million yuan in annual salary. Li is a rare tech genius who has already changed his ways and should be given an opportunity, said his defense lawyer.