South Korea's financial-sector hacking wave has widened to a brokerage, an asset manager and a cryptocurrency exchange. Daishin Securities confirmed on Wednesday that personal and credit information belonging to 38,490 customers had been leaked. It said it detected unauthorised access on 17 October to a server supporting remote account opening, blocked the addresses used, and confirmed the leak on 26 October. Exposed data included names, addresses, bank and securities account numbers and mobile numbers.

Police open a joint investigation

Police opened a preliminary inquiry on 28 October into the breaches at Daishin, Mirae Asset Global Investments and Bithumb, assigning it to the team already handling earlier financial-sector hacks. Investigators said they were comparing attack methods and had not ruled out a single perpetrator, although no link has yet been confirmed. Bithumb said attackers reached its internal mobile system and it was checking whether customer data was exposed; Mirae Asset said some internal business data was viewed but no personal credit information had leaked.

Policy debate gathers pace

The latest disclosures follow an earlier October wave in which the Financial Services Commission said cyber incidents had been identified at 16 firms, with roughly 100,000 records exposed. Regulators have ordered customer notifications and urged urgent patching. Experts warned attackers were moving from banks to weaker externally connected systems, such as account-opening servers, which could offer a foothold into deeper networks. For customers, the immediate risk is phishing and targeted fraud using leaked names, contact details and account information.

The episode is fuelling a policy debate in Seoul, where critics say delayed digital finance safety legislation has left governance lagging behind attacks. Authorities have announced vulnerability inspections running until the end of 2026. The firms said they will compensate customers where damage is shown, and customers were advised to verify any contact claiming to come from their broker through official channels.

Sources: Aju Press and Seoul Economic Daily.