Aflac Japan Hack Exposes Data of 4.38 Million Customers

Aflac is a major U.S. insurer with a large customer base in Japan, where it primarily offers medical and cancer insurance. Insurers retain identity and financial account information for long periods, and a breach can compromise personal privacy while creating risks of fraud, identity theft and financial harm. The incident has therefore drawn close attention.

Aflac’s Japan unit detected a system intrusion in late June 2026. An investigation estimated that personal information belonging to about 4.38 million customers, including names and insurance account details, was exposed. Bank account information used for premium payments was also accessed for about 230,000 people. The company said customers’ credit card information was not affected.