Four men were charged Tuesday in a Chinese court for creating and selling the worm that went by names such as "Fujacks" and "Panda Burning Joss Sticks," according to the Changjiang Times.

The quartet, which included Li Jun, the 25-year-old most frequently pegged as Fujack's maker, faces prison terms of at least five years if convicted, the southern Chinese newspaper said. The other defendants listed were Wang Lei, Zhang Shun and Lei Lei. Last February, in the first arrests in China for writing malware, six were taken into custody by Hubei provincial police. It's unclear whether the charges against the remaining two have been dropped.

Fujacks/Panda, which was written in October 2006, was spread through an infected Web site and reportedly compromised about a million Windows-powered PCs in China. Earlier this year, police accused Li Jun of selling the worm to others and pocketing US$13,000 (AU$16,076) in the process, although yesterday's account in the Changjiang Times put Li's total take at more than US$19,000.

Others facing charges also allegedly made money from the sale of the worm, which among other actions, steals online game usernames and passwords. For instance, Wang received US$10,500, while Zhang received US$1,500.

The average annual income for Chinese living in urban areas is currently around US$925.

Li also made news this spring when police made him write software that was supposed to wipe Fujack from infected PCs. Local police said then that they would release the tool, but there has been no confirmation that authorities ever let it loose. Shortly after the news broke, Symantec researchers analyzed a copy and said it was nearly worthless.

"In our internal testing, the tool was generally ineffective," said Zulfikar Ramzan, a senior principal researcher at Symantec's security response group, in March. "On three, it was completely ineffective, and on five, it left a lot of traces of the worm on the system. Those remnants, registry keys or files, may not actually do anything bad, but they make the system dirtier than it used to be."

Reports from China have not said when Li and the others would face trial in People's Court.