OK Savings Bank has confirmed an additional leak of customer data, this time involving deposit holders, following an earlier breach affecting loan applicants. The latest incident affected about 200 customers, a scale similar to the previous case, and exposed not only names and account numbers but also deposit balances and applicable interest rates.
The bank confirmed the leak on the 15th and sent notices to some customers on the morning of the 16th, according to financial industry sources.
The data was leaked through the bank's mobile account inquiry service. The exposed information included customer names, account numbers, product names, account opening dates, account balances, interest rates and dates of last transaction. The items actually exposed may differ from customer to customer. The breach is believed to have affected about 200 people.
OK Savings Bank said it blocked the access route immediately after detecting the leak and strengthened security measures and monitoring. The bank also warned customers of the possibility of secondary damage, including identity theft, voice phishing and pharming using the leaked information.
The incident follows a previously confirmed leak of personal data belonging to loan applicants. The bank earlier confirmed that unauthorized parties gained abnormal access to a loan application page on its website on the 11th and 12th of this month, exposing the personal data of 250 customers.
That breach was initially estimated to have affected 183 people, but the figure rose to 250 during a detailed investigation. It has not yet been confirmed whether the latest leak of deposit customer data resulted from the same attack as the earlier incident.