South Korea Hit by a Fresh Wave of Financial Hacks: 38,490 Customers Exposed at Daishin as Bithumb and Mirae Asset Report Breaches

South Korea's financial industry is absorbing a second wave of cyberattacks in roughly a month. Brokerage Daishin Securities, asset manager Mirae Asset Global Investments and crypto exchange Bithumb all disclosed incidents this week, according to TechCrunch and Korea's Yonhap News Agency, in a stretch that is turning AI-assisted hacking from a hypothetical risk into a measurable pattern across Asian finance.

Daishin reported that a cyberattack exposed the personal information of 38,490 customers, including names, email addresses and mobile phone numbers. The company has notified affected customers, is cooperating with authorities in the investigation, and says it will compensate for any losses as required by law.

Mirae Asset and Bithumb reported separate cybersecurity incidents on Wednesday. Neither has confirmed that customer data was taken. South Korea's Financial Services Commission has called for stronger cybersecurity measures following the string of attacks on financial firms and government agencies, and the country plans to conduct security checks on dozens of IT systems in the private sector.

The backdrop matters. In September, hacking incidents were found at 16 South Korean financial firms, and security researchers at CrowdStrike linked that wave to a suspected China-based hacker who relied on an AI penetration-testing tool called Artex — a case Microsoft separately highlighted as an example of an agentic AI framework being repurposed for intrusion. Officials are still investigating the root cause of the latest breaches, and no connection between the September and October waves has been established.

The pressure is regional. On Monday, Japan's GMO Internet said hackers posted stolen customer data online, the latest in a series of attacks on Japanese financial institutions. Investigators have not established links between the Korean and Japanese incidents, but the pattern — brokerages, asset managers and crypto exchanges hit in clusters — suggests the sector's attack surface is being probed systematically rather than opportunistically.

The structural worry is cost asymmetry. AI penetration-testing tools compress what used to require a skilled team into a scripted workflow, and financial institutions hold exactly the combination attackers want: customer PII, trading accounts and digital assets. South Korea's response — regulator pressure plus mandatory security checks across dozens of private-sector systems — treats the wave as an industry problem, not a set of isolated breaches. The next test is whether the October attackers used the same tooling, which the ongoing investigation should clarify.