Key facts
- Bithumb confirmed a data breach on October 28, affecting its internal mobile groupware system.
- Customer virtual assets are safe as the compromised system is on a separate network.
- The breach is part of a wider wave hitting at least 20 South Korean financial firms.
- Daishin Securities reported a breach affecting 38,490 customers' personal and bank details.
- Authorities suspect AI-assisted attacks, with many source IPs linked to North Korea.
South Korea's second-largest crypto exchange, Bithumb, confirmed a data breach on October 28, stemming from unauthorized external access to its internal mobile groupware system the previous day. The compromised system, Daou Office, is an outsourced employee messaging platform. Bithumb has reported the incident to the Korea Internet & Security Agency (KISA) and the Personal Information Protection Commission. The exchange emphasized that customer virtual assets are safe as the affected system operates on a network entirely separate from its trading platform. This breach is part of a broader trend impacting South Korea's financial sector, with at least 20 firms reporting cyber incidents. Daishin Securities also confirmed a breach affecting personal and bank details of 38,490 customers, while Mirae Asset Global Investments detected abnormal access but reported no investor information was compromised. Authorities are investigating, with many source IP ranges linked to North Korea, though definitive attribution remains cautious. The attack pattern is suspected to be AI-assisted and may be connected to a Shinhan Bank breach in September.