A 29-year-old man was sentenced to three years in prison Tuesday by the Osaka District Court for creating a computer virus and planting it in an acquaintance's personal computer.

Hirotada Kobayashi pleaded not guilty at the court's Sakai branch, claiming he wasn't the perpetrator. He was the first person charged for the crime of creating a computer virus, made possible under a penal code revision in 2011.

According to the court, Kobayashi produced in September 2011 a virus programmed to automatically generate and post the threatening message — "I can kill you anytime" — on an online bulletin board he was running and infected the acquaintance's PC with the virus. Kobayashi had trouble with his acquaintance.

After the message was posted from the acquaintance's computer, Kobayashi filed a police report falsely claiming he was a victim of intimidation, the court said.