It has been a long time coming, but a virus writer has finally been arrested by the Japanese authorities. According to security specialists Sophos law enforcement agencies in Kyoto, Japan, have arrested three men who stand accused of plotting to infect users of a popular P2P file-sharing network with a Trojan. The Trojan itself displays images of popular anime characters on-screen, all very lovely and Japanese, while at the same time deleting MP3 and movie files from the system: not so nice, obviously.

The malware which was targeted at Winny P2P users has been identified as ‘Harada’ in various media reports and Sophos say this is related to the similar Pirlames Trojan horse which it first reported intercepting in Japan last year. According to Japanese media reports, the three men have admitted their involvement in the crime. One of the men is said to have written the malware, while the other two are believed to have distributed the malicious code via Winny.

"It isn't illegal to write viruses in Japan, so the author of the Trojan horse has been arrested for breaching copyright because he used cartoon graphics without permission in his malware. Because this is the first arrest in Japan of a virus writer, it's likely to generate a lot of attention and there may be calls for cybercrime laws to be made tighter," said Graham Cluley, senior technology consultant for Sophos. "Malware is truly a global menace, impacting on every user of the internet, and it is good to see police around the world doing their bit to tackle the problem."

Isamu Kaneko, the author of the Winny file-sharing program, was fined by a Japanese court in December 2006 for assisting in copyright violation. The rights and wrongs of the case have been widely debated on the internet. A survey conducted in 2006 by Sophos reflected the serious concern that uncontrolled applications are causing system administrators:

• 86.5 percent of respondents want to block P2P applications
• 79 percent say that blocking is essential

"Businesses are increasingly looking to control users' access to P2P file-sharing software not just because they can eat up bandwidth or infringe copyright laws, but also because they can present a security risk to corporate data," continued Cluley. "This music and movie-munching Trojan horse is a timely reminder of the danger malware can pose to a company's network."