Three South Korean financial firms have reported data breaches on the same day, according to Yonhap News Agency, in the latest sign of a sustained hacking wave against the country's financial sector. Crypto exchange Bithumb, brokerage Daishin Securities and asset manager Mirae Asset Global Investments all confirmed incidents, Reuters reported on 28 October 2026.

Daishin reports 38,000 records leaked

Bithumb said its in-house mobile system had been hacked and personal information leaked, and it was investigating whether member data was included. The exchange said its internal work system is separate from its cryptocurrency trading platform, so the breach does not give access to customers' crypto assets. It notified the Korea Internet and Security Agency and the Personal Information Protection Commission on the same day the breach was discovered.

What customers should do now

Daishin Securities said about 38,000 pieces of customer information had been leaked and that it had taken emergency measures. Mirae Asset Global Investments also confirmed a hacking incident, with authorities assessing the situation. Spokespeople for the three firms could not immediately be reached for comment when Reuters reported the incidents.

The reports follow a broader run of attacks. South Korea's Financial Services Commission said earlier in October that hacking attacks at 16 financial firms, including banks, had caused around 100,000 cases of data leaks so far.

Customers should watch for official notices from the companies themselves, rather than acting on unsolicited messages claiming to be from them. Anyone contacted about account changes should verify the message through the firm's official app or website, and change passwords reused elsewhere. The full extent of the Bithumb leak was still being assessed at the time of reporting.

Sources: Reuters via The Hindu BusinessLine and Reuters via Duke FM, both reporting Yonhap.