Shinhan Financial Group's (KRX:055550) banking arm Shinhan Bank disclosed a breach that led to the leak of personal data of about 25,000 clients, according to a Thursday statement.

The leaked data consists of client names, phone numbers, annual income and calculation limits related to loan applications.

An unauthorized external person obtained the information from some of the bank's services through abnormal methods.

The bank launched its company-wide emergency response system after detecting the leak and completed emergency measures. It will also carry out measures to prevent recurrence.

The bank apologized for the incident and will take responsibility for losses.