The country's financial watchdog has pinpointed 28 internet protocol (IP) addresses in the United States, Japan and 10 other countries used for a series of recent hacking attacks Korean financial institutions, industry sources said Tuesday. Several financial companies, including Hana Bank, KB Kookmin Bank and Shinhan Bank, suffered back-to-back leaks of customer information in recent hacking attacks last week, raising concerns that more firms might have suffered data breaches. According to the sources, the Financial Supervisory Service (FSS) has shortlisted IP addresses in 12 countries as of 6:00 p.m. on Monday, which are presumed to have been used for the artificial intelligence (AI) agent-backed hacking. But it has not been able to pinpoint the locations of some of the IP addresses, they said. Local financial firms have been in a hurry to check their own security systems to fend off any additional hacking attempts. Over the weekend, President Lee Jae Myung called for a thorough investigation into the attacks. On Thursday, Shinhan Bank said personal information of around 25,000 customers,