Unauthorized access to MS&AD insurers' policyholder portal: Mitsui Sumitomo Insurance and Aioi Nissay Dowa leak about 480,000 customer records

MS&AD group insurers Mitsui Sumitomo Insurance and Aioi Nissay Dowa said on Nov 6 that unauthorized access to their policyholder portal was detected on the night of Nov 2, related services were halted late on Nov 3, and the investigation confirmed a data leak ^[1][2]. About 37,000 records leaked at MSI and about 444,000 at Aioi Nissay Dowa, including policy numbers, names, addresses, phone numbers and emails, with 3 partial card numbers and 19 partial bank account entries at Aioi; iThome reports more than 720,000 records across four group companies ^[1][2][3]. Policyholders should beware of impersonating emails, SMS and calls and must not click links or enter passwords or card details ^[1][2].

Industries mainly affected: Finance

Policyholders should beware of impersonating emails, SMS and calls and must not click links or enter passwords or card details