On May 11, 2026, the General Incorporated Foundation Shin-Nihon Certification Association announced that, as a result of a cyberattack against the organization, personal data—including customer information belonging to major non-life insurance companies for which it had been providing outsourced services—may have been leaked to external parties.
On the same day, the following insurance companies disclosed details of the incident:
- Mitsui Sumitomo Insurance Company, Limited
- Tokio Marine & Nichido Fire Insurance Co., Ltd.
- Sompo Japan Insurance Inc..