GMO says cybersecurity team found clues that could identify hackers

GMO Internet Group said its cybersecurity investigators had uncovered information that could help identify those responsible for unauthorized access involving clients’ personal data. CEO Masatoshi Kumagai said on X that the findings had been passed to police and other relevant parties to help secure an arrest or an international wanted notice.

The company said 270 tips arrived during the first day of its $1 million reward offer. The bounty will run for a year unless the perpetrator is arrested or added to an international wanted list before then, GMO said.

The group allegedly behind the attack had demanded a $1 million ransom and threatened to disclose information about one compromised account holder each day if GMO did not pay. After the company refused, details apparently belonging to one customer appeared on the group’s website.

That website was subsequently taken down, and the group has made no further public statements. The Internal Affairs and Communications Ministry reportedly asked telecommunications carriers, through industry organizations, to block websites publishing the leaked customer information.

GMO urged people not to visit or circulate such websites, saying the perpetrator collected information about visitors. Before its website went offline, the alleged hacker group claimed an outside source had supplied details of GMO security vulnerabilities after receiving no response to warnings submitted through the company’s online contact form over several months.