Japanese Virus Writer Jailed for Two and a Half Years

A Japanese man was sentenced to two and a half years in prison for creating and spreading a data damaging piece of malware commonly known as the ika-tako virus.

Masato Nakatsuji, 28, from Izumisano, Osaka Prefecture, created ika-tako - squid-octopus in Japanese - sometime in 2009, according to his own account.

However, he only began distributing it on the popular Winny peer-to-peer file-sharing network in May 2010. The virus replaced people's files with illustrations of a squid (ika) and an octopus (tako).

Nakatsuji admitted to creating the virus and said that it infected around 50,000 computers. He was arrested in August and charged with destruction of property.

Nakatsuji previously received a two-year suspended prison sentence in 2008 for creating a different piece of malware known as "Harada" which had a similar payload.

"It was an ingenious, planned crime to spread a computer virus over a long period of time. The defendant committed the crime while he was on probation for a similar charge. I have no choice but to give him a sentence without suspension," said Judge Masaru Okabe of Tokyo District Court on Wednesday when handing out the sentence.

Nakatsuji was on the receiving end of two out of three jail sentences ever given in Japan for offenses related to malware development. In fact, writing malware was not a crime in the country until last month when the Japanese parliament enacted new legislation.

Japanese malware writers used to be charged with destruction of property if the malware caused any actual damage. However, according to the new law, they face sentences of up to three years in jail and fines of up to 500,000 yen (US$6,200).

In fact, even the act of simply storing or acquiring malware is punishable with up to two years in prison and a fine of 500,000 yen. Japan introduced the new law after a rise in the number of malware attacks in the country.