Japanese Virus Writer Arrested for the Second Time

It seems that a previously convicted Japanese virus writer just can't help himself from developing malicious programs and infecting users. The man was arrested this week for the second time in two years due to damages caused by his new malware.

The Daily Yomiuri reports that this Monday the Metropolitan Police Department arrested Masato Nakatsuji, 27, from Izumisano, Osaka Prefecture, on charges of destroying property. The man is suspected of creating a data-damaging computer virus and spreading it on file sharing networks.

Nakatsuji's malware is known as “ika-tako” because it displays illustrations of a squid (ika) and an octopus (tako). Apparently, the vxer (virus writer) already admitted to creating the malicious application, which he claims infected around 50,000 computers so far.

Police started investigating the incident after one of the 20,000 people confirmed as affected, filed a complaint that the virus destroyed his data. The 37-year-old victim said that he downloaded the malware onto his computer in June via the Winny file-sharing application. This correlates with Nakatsuji's account, who told police that he created ika-tako around a year ago, but started distributing it on the peer-2-peer network this May.

What's interesting about this case, is that it is the second time when the Japanese man is arrested on charges related to malware authoring. Nakatsuji was previously convicted in 2008 for writing the Harada virus, a destructive piece of malware which replaces numerous file types with images of a Japanese comic book character. According to Graham Cluley, senior technology consultant at Sophos, this malware is also known as Pirlames.

Last time, Nakatsuji was charged with defamation and violating the copyright law, for which he received a two-year suspended prison sentence. The vxer, who now accounts for two of the total three arrests related to malware authoring in Japan, said that this time he was confident he wouldn't be caught.

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