TOKYO –
GMO has announced a reward totaling approximately 150 million yen for information leading to the identification of hackers responsible for a cyberattack on its systems, while also pledging compensation to customers whose personal information has been exposed, as Japan faces a growing wave of cyberattacks targeting major companies.
The hacking group believed to be behind the unauthorized access has threatened to release personal information belonging to customers who used GMO’s servers unless the company pays a ransom.
In response, GMO said it would offer a total reward of approximately 150 million yen for information that could help identify those responsible. A dedicated reporting channel will open at noon on October 28 to receive information related to the attack.
The company also announced that it would make special compensation payments to customers whose personal information has been confirmed to have been publicly disclosed.
Compensation will vary depending on the sensitivity of the information exposed. Customers whose names, contact details or similar personal information have been disclosed will receive 10,000 yen, while those whose account IDs, passwords or other account credentials have been exposed will receive 15,000 yen.
The announcement comes as Japanese companies confront an increasing number of cyberattacks involving the theft of personal information, disruption of business operations and demands for ransom payments.
One of the most recent major incidents involved parking and car-sharing operator Park24, which disclosed unauthorized access to systems operated by its Times Car service in September 2026. The breach affected approximately 6.62 million customer accounts, with investigators identifying evidence that encrypted images of identification documents, including driver’s licenses, belonging to about 1.46 million users had been transferred outside the company.
On October 23, Park24 announced that affected customers would receive compensation worth 3,000 yen in cash or gift cards. The company expects to record an extraordinary loss of approximately 5.5 billion yen, including compensation and other expenses related to the incident.
Japan’s insurance industry has also been affected. In June 2026, Aflac Life Insurance Japan disclosed unauthorized access to systems containing personal information associated with approximately 4.38 million policyholders. The exposed information included names, addresses and telephone numbers, prompting an investigation and measures to protect customers.
In July 2026, frozen-food producer and logistics operator Nichirei suffered a cyberattack that disrupted refrigerated warehouse operations and shipments of frozen-food products. The disruption affected deliveries to restaurants, supermarkets and school lunch programs. A hacking group calling itself RansomHouse subsequently claimed responsibility, although Nichirei had not confirmed the group’s involvement.
The attacks followed two particularly damaging incidents in 2025 involving major Japanese businesses.
In September 2025, Asahi Group Holdings, one of Japan’s largest beverage producers, was struck by a ransomware attack that disrupted production, ordering and distribution systems. The company temporarily suspended operations at its six domestic beer factories before gradually restoring production.
A ransomware group known as Qilin claimed responsibility and said it had stolen thousands of internal files. Asahi subsequently confirmed that some company information had been stolen and investigated the possible exposure of personal information. The incident demonstrated how a cyberattack could disrupt not only computer systems but also manufacturing and distribution across a major consumer goods business.
In October 2025, online office supplies retailer Askul was hit by a ransomware attack that forced it to suspend orders and shipments through its Askul and Lohaco shopping services. The disruption extended to other retailers, including Muji and Loft, whose online operations relied on Askul’s logistics network. Recovery took several months, with Askul restoring sales of all products in January 2026.
An earlier high-profile incident involved publishing and entertainment group Kadokawa, which suffered a major ransomware attack in June 2024. The attack disabled its popular Niconico video-sharing service and disrupted publishing and other business operations.
Kadokawa later confirmed the exposure of personal information belonging to 254,241 people, including employees, business partners and individuals connected to educational institutions operated by the group. The attack illustrated the potential for stolen corporate information to be distributed publicly after hackers gain access to internal networks.
The growing frequency and scale of such incidents have raised concerns about the vulnerability of Japan’s corporate information systems. By October 20, 2026, Japan had recorded 723 cybersecurity incidents, already exceeding the annual totals reported for both 2024 and 2025.
Cybersecurity specialists have warned that attackers are increasingly exploiting weaknesses in corporate networks and using automated tools to identify vulnerable systems. Some groups use ransomware to encrypt data and interrupt operations, while others steal sensitive information and threaten to release it unless payment is made.
For companies handling large volumes of customer information, the consequences can extend beyond immediate system repairs to include compensation payments, legal liabilities, lost business and damage to public confidence.
GMO’s decision to offer a reward of approximately 150 million yen represents a particularly aggressive attempt to identify those behind a corporate cyberattack. Combined with its compensation scheme for affected customers, the move reflects mounting pressure on Japanese companies to respond more decisively to data breaches as cybercriminals increasingly target both sensitive information and essential business operations.
Source: TBS