Data Breaches Aflac Japan Data Breach Impacts 4.38 Million Hackers accessed the insurance giant’s policyholder portal multiple times between June 15 and June 25. By Ionut Arghire | June 30, 2026 (8:52 AM ET) Flipboard Reddit Whatsapp Whatsapp Email Aflac Life Insurance Japan, a subsidiary of insurance giant Aflac, on Tuesday announced that hackers stole the personal information of 4.38 million customers. The company’s systems were hacked on June 15, and the attackers accessed them several times until June 25, when the data breach was discovered, Aflac said in a filing with the US Securities and Exchange Commission. “Upon identifying the unlawful access, Aflac Japan promptly took steps designed to contain the incident and prevent further intrusion, including suspending certain systems,” Aflac said. The incident is limited to certain Aflac Japan systems and does not affect Aflac’s systems related to the US business, the insurance giant told the SEC. According to an FAQ published on Aflac Japan’s website, at least five services have been disrupted as a result of the incident. For the time being, the company could not estimate when the affected services may be restored. Aflac Japan says the attackers exfiltrated data from its policyholder portal, and that approximately 4.38 million customers and agents are likely affected. Advertisement. Scroll to continue reading. The compromised personal information includes names, addresses, phone numbers, dates of birth, gender, security information, and insurance account information. According to the company, the insurance premium transfer account information of roughly 230,000 people was also exfiltrated, but no credit card information was accessed. Aflac Japan also notes that the types of exposed information vary by individual and that each customer will receive a notification letter containing specific details on the matter. The company also noted that its investigation into the attack is ongoing, supported by third-party cybersecurity experts. Aflac Japan also notified the relevant authorities. Related: Insurance Regulators Group NAIC Hit in Oracle PeopleSoft Hack Related: More Klue Breach Victims Identified as Hackers Get Hacked Related: Canadian Electricity Provider London Hydro Discloses Data Breach Related: Xsolis Data Breach Affects 1.4 Million Individuals Written By Ionut Arghire Ionut Arghire is an international correspondent for SecurityWeek. Daily Briefing Newsletter Subscribe to the SecurityWeek Email Briefing for the latest cybersecurity threats, trends, and expert insights. 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