Investigators claim he used ChatGPT to assist in writing a program that automated unauthorised access to member accounts, resulting in the cancellation of 46,812 subscriptions.
A 15-year-old high school student in Japan has been arrested for allegedly using ChatGPT to help develop software that was used in a cyberattack on Bandai Namco Filmworks’ Bandai Channel streaming service. The attack disrupted operations and forced the cancellation of more than 46,000 user accounts.
According to reports citing the Tokyo Metropolitan Police, the teenager is suspected of fraudulent obstruction of business after allegedly exploiting a vulnerability in the anime streaming platform in November 2025. Investigators claim he used ChatGPT to assist in writing a program that automated unauthorised access to member accounts, resulting in the cancellation of 46,812 subscriptions, Straits Times reported.
“I created the source code for the withdrawal process myself. Since the processing was taking a long time, I asked ChatGPT and completed it in a different programming language,” he said.
Police allege that on November 4, 2025, the teen sent fraudulent commands to Bandai Channel’s servers, triggering the mass deregistration of thousands of accounts. The attack disrupted the company’s services beginning November 6, with full operations only resuming in December after repairs to its systems. Bandai Namco Filmworks later reported the incident to police.
Investigators believe the teenager identified a security flaw in the platform and exploited it to gain unauthorised access to account information. The attack also forced the company to temporarily suspend parts of its service. Authorities further allege that even after the company blocked his access, the teen changed his IP address about 30 times to continue sending malicious commands.
The suspect, who was a junior high school student at the time of the alleged attack, had already been arrested in June this year in connection with other computer-related offences. He reportedly taught himself programming while in elementary school.
During questioning, the teenager allegedly admitted to the accusations and told investigators he had “no grudge” against Bandai Namco Filmworks. Instead, he said he targeted the platform simply because “there were many accounts I could log into”.
“I started using computers when I was in the fourth grade and taught myself everything I know. I happened to be able to access the information and had nothing against the company,” he said.
After the breach, Bandai Namco Filmworks notified affected customers individually and urged them to be cautious of phishing and impersonation emails. Users whose memberships had been cancelled were asked to re-register, while the company also announced refunds for subscription fees charged during the service disruption.
Bandai Namco Filmworks said there is no evidence that the leaked data has been published online or misused.
“We take this situation very seriously and will continue to conduct regular checks and strive to prevent any recurrence,” the company said.
