Police on Tuesday referred a 13-year-old boy in Osaka to a juvenile consultation center after he was suspected of providing instruction on how to obtain a basic smartphone virus through an online marketplace.
The boy, a second grader at a junior high school, has admitted to the allegation and was quoted by the police as saying he did it for pocket money.
Providing information or instruction about how to obtain computer or smartphone viruses is a crime.
Four boys allegedly paid for the information, but no damage from the virus has been reported, investigators said.
Once infected with the virus, a smartphone screen is filled with images of human faces, the police said.
The boy is suspected of selling the information on the Mercari smartphone shopping application in March, and then selling it to the four — aged 14 to 19 — for points worth about ¥5,000 ($46) in total that can be used on the app.
He was referred to a juvenile consultation center because those under 14 cannot be held criminally liable for their actions.
The police also referred the four teenagers in Nagano, Kyoto and Hyogo prefectures to prosecutors on suspicion they attempted to download the virus illegally. They said they bought the information for a prank, according to the investigators.
A cyber crime investigator in Nara Prefecture found the virus information allegedly posted by the boy in mid-March, the police said.
Mercari Inc. launched its platform in 2013, enabling users to buy and sell items via a flea market style app.