Bithumb internal groupware hacked, employee data leaked

South Korean crypto exchange Bithumb detected unauthorized access by an outside party to its internal mobile groupware system on Oct 27 2026, leading to a personal data leak, and reported it to KISA and the Personal Information Protection Commission the same day. Information found so far mainly concerns employees, such as names, departments and contact details, but Bithumb has not ruled out that customer information shared in internal work files was included and is still analyzing the scope. Bithumb says its exchange systems are physically separated from the groupware and no crypto was stolen. Daishin Securities and Mirae Asset Global Investments reported separate breaches the same day.

Why this severity: Employee data confirmed, customer data possibly included and still being analyzed; no funds stolen, but exchange staff and customer contact data is prime material for phishing and social engineering

Started

Oct 27, 2026

• #Bithumb
• #Crypto
• Data breach
• #South Korea
• #Phishing

Notes & caveats

The attacker and intrusion method are still under investigation. Money Today reports Bithumb staff used Daou Technology's DaouOffice groupware (messenger and file sharing) and that the initial entry point is believed to be the groupware, but neither Bithumb nor Daou has confirmed a flaw in that product. Bithumb said it would publish details of the incident and the leaked data.