According to the authorities, data involving some 50,000 clients have been stolen from Citibank Korea Inc. and Standard Chartered Bank Korea.
The authorities said the additionally leaked data do not include critical information such as credit card numbers or passwords, making it unlikely that they would be used by financial scammers.
But worries of financial fraud grew after the police announced Wednesday that several clients at Citibank Korea have been scammed by a voice phishing ring that used their personal information stolen from the bank last year. Data on some 2,000 customers of Citibank Korea, including financial transaction records, were used by the ring, according to the police.
Following the leak, the regulator and other related government agencies have been working to prevent a recurrence of such a massive breach.
The regulator also has warned stern punishment to the firms and their managers, including fines equivalent to 3 percent of annual sales with no ceiling.
