Unauthorized access occurred to the systems of ユミルリンク, which handles email distribution for Resona Group, and information including customers' email addresses and management numbers may have been leaked. The information is not believed to include financial transaction data such as account numbers, PINs or credit card information.
Resona Bank, Saitama Resona Bank and Kansai Mirai Bank, which belong to Resona Group, announced on the 27th that customer information may have been leaked. The cause was identified as unauthorized access to the systems of ユミルリンク, which handles email distribution services on the banks' behalf.
The potentially leaked information includes email addresses and customer management numbers, while financial transaction data such as account numbers, PINs and credit card information is not included, according to the announcement. ユミルリンク reportedly confirmed unauthorized access in the early hours of the 16th and was informed on the 26th that information it held may have been leaked.
Resona Group apologized for causing significant concern and inconvenience to those affected. ユミルリンク provides email distribution services for companies and local governments and announced on the 26th that personal information, including email addresses, totaling 51.62 million records had been leaked.