South Korea's Five Largest Commercial Banks Hit by Cyberattacks

South Korea's financial sector faced an unprecedented cybersecurity crisis in early October as its five largest commercial banks were simultaneously targeted by cyberattacks. The incidents, suspected to involve artificial intelligence, resulted in customer data leaks from three of the institutions.

According to news reports, KB Kookmin Bank and Hana Bank both reported customer information breaches stemming from suspected AI-assisted attacks. BNK Busan Bank confirmed that personal information of 11 outsourced employees was leaked during an attack. Shinhan Bank had previously experienced a similar incident leading to the exposure of data for approximately 25,000 customers.

KB Kookmin Bank stated that information for 119 customers was leaked, including names, phone numbers, addresses, and encrypted resident registration numbers. The bank clarified that the attack targeted an internal mobile work support system for employees and did not affect online or mobile banking services. Hana Bank reported that data for 89 customers was compromised, including resident registration numbers, names, addresses, email addresses, phone numbers, and employment details. The bank specified that the breach occurred via an external business support system (ODS), which is independent of customer transaction systems.

Woori Bank and NH Nonghyup Bank also reported similar attempted intrusions, but their security systems successfully intercepted these attempts without any data loss. These events highlight the growing cybersecurity challenges for financial institutions, particularly in the face of evolving attack vectors enabled by AI.