Five major South Korean banks hit at once; three report data leaks

South Korea's five major commercial banks were hit simultaneously by what is suspected to be an AI-driven hacking campaign, and three of them suffered customer data leaks, according to a report from IT之家 on October 3 citing Yonhap. It is the first time all five of the country's major banks have been attacked at the same time.

Citing information released by South Korean financial authorities on October 2, the report said Shinhan Bank was the first to be disclosed as a victim, followed by KB Kookmin Bank and Hana Bank, which were also hit by suspected AI-driven attacks that led to customer data leaks.

The scale of the leaks varies by bank. Around 25,000 customers of Shinhan Bank were affected. KB Kookmin Bank said 119 customers had information exposed, including names, phone numbers, addresses and encrypted resident registration numbers, with the specific data differing from customer to customer. Hana Bank said 89 customers were affected, with leaked details including resident registration numbers, names, addresses, email addresses, phone numbers and employers. The report also noted that BNK Busan Bank had the personal information of 11 outsourced workers exposed as a result of the attack.

As for how the attackers got in, the report said the target was an employee-only mobile work support system, which is kept separate from the online and mobile banking systems customers use for financial transactions. Hana Bank said the incident stemmed from external hackers illegally accessing its business support system (ODS). At the time of the report, the situation remained at the stage where individual banks were confirming and disclosing the number of people affected.