Japan Cyberattack & Data Breach Map (2025–2026): Officially Disclosed Incidents by Prefecture

Cyberattacks and data breaches that companies, universities, local governments, hospitals and other organisations in Japan have disclosed themselves since January 2025, counted by prefecture of the organisation's head office. Each entry links to the organisation's own notice (for listed companies, this can be a stock exchange filing). The location is the head office, not necessarily where the damage happened. Incidents that were not disclosed are not included. When an attack on a contractor affected many organisations, it is counted once, under the company that was attacked, with the affected organisations shown in the same entry. Beware of follow-up scam calls and emails that pretend to come from affected organisations.