Bithumb Says Breach Exposed Data of 6,444 Users, Most Was Encrypted

Bithumb said information for 844 users was readable after unauthorized external access to its Daou Office work system on Oct. 27, exposing identity and banking details.

Information for 5,600 of the 6,444 affected users was encrypted and unreadable. The exposed details included names, phone numbers, email addresses, resident registration numbers, driver’s license numbers, bank account numbers and copies of identity cards. Information tied to 715 employees and partner personnel was also exposed.

Bithumb said Daou Office is separate from its exchange account and asset systems and that it found no direct intrusion into Bithumb’s trading systems or customer database. It blocked access, disabled the affected system and filed incident reports with the Korea Internet Security Agency (KISA) and Personal Information Protection Commission (PIPC). The company also strengthened real-time monitoring for unusual trading and withdrawals.

The update expands on Bithumb’s earlier notice that it was checking for customer data exposure.