South Korean brokerages and crypto exchange Bithumb hit by new wave of cyberattacks

South Korea's financial industry is contending with another round of cyberattacks, this time hitting two brokerages and a major cryptocurrency exchange. According to TechCrunch, Daishin Securities, Mirae Asset Global Investments and the crypto exchange Bithumb have all reported security incidents, roughly a month after an earlier wave of attacks on South Korean financial institutions.

What we know about the breaches

Daishin disclosed an attack that exposed the personal information of 38,490 customers, including names, email addresses and mobile phone numbers, according to local media reports cited by TechCrunch. The brokerage has notified affected customers, is cooperating with authorities on the investigation, and has said it will compensate customers for any losses as required by law.

Mirae Asset Global Investments and Bithumb separately reported cybersecurity incidents on Wednesday, per local media, though neither company has confirmed that customer data was taken.

TechCrunch added that South Korea's Financial Services Commission, Daishin, Bithumb and Mirae Asset did not immediately respond to requests for comment.

A possible echo of September's attacks

The timing is notable. The new incidents come about a month after a series of attacks on South Korean financial institutions, a campaign that security researchers linked to a suspected China-based hacker who relied on an AI-powered penetration testing tool called Artex. However, officials are still investigating the root cause of the latest breaches, and no connection between the two waves has been confirmed.

The earlier September attacks also raised concerns that vulnerabilities extend beyond the country's banking system, as the latest targets now include securities firms and a crypto platform.

Regulators push for stronger defenses

South Korea's financial regulator has called for stronger cybersecurity measures following a string of attacks on financial firms and government agencies, according to officials in Seoul on Wednesday. The country also plans to conduct security checks on dozens of IT systems in the private sector.

The problem is not confined to South Korea. Japan has also reported a cybersecurity incident involving GMO Internet, following a series of attacks on its own financial institutions. Investigators have not established a connection between the incidents across the region, but as TechCrunch notes, the pattern points to cybersecurity challenges that have built up over years of weak defenses across Asian financial sectors.

Why it matters

The repeated targeting of South Korean financial firms within a single month suggests the sector's defenses are not keeping pace, and the involvement of a crypto exchange broadens the potential blast radius beyond traditional banking. The September campaign's link to Artex, an AI penetration testing tool, is the more unsettling signal: offensive AI tooling appears to be moving from research demos into active campaigns against real financial targets. Even if the latest breaches turn out to be unrelated, regulators are already responding with audits and calls for tougher security requirements, and Daishin's pledge to compensate affected customers shows the legal and financial exposure institutions face when customer data leaks.