TOKYO — In a first for Japan, a 25-year-old man, Ryuki Hayashi, was convicted by the Tokyo District Court on October 25 for creating a computer virus using generative artificial intelligence. The court found Hayashi guilty of creating illegal digital records and sentenced him to three years in prison, with a suspension period of four years.
Prosecutors had sought a four-year sentence, but the court issued a slightly more lenient sentence, allowing Hayashi to avoid immediate incarceration. Hayashi created the virus, which operated similarly to ransomware, in his Kawasaki home using his computer and smartphone around March 31, 2023. He reportedly acquired the malicious program’s source codes through generative AI and later purchased SIM cards under false identities, a tactic often used to cover illegal activities.
This ruling is significant as it marks the first criminal case in Japan involving the misuse of generative AI, highlighting the increasing risks associated with AI-enabled cybercrime and setting a precedent in Japan’s legal system.