Bithumb disclosed that a 2017 hacking incident involving an employee personal PC exposed customer personal information, with later company reporting describing about 30,000 affected users and exposed names, email addresses, and phone numbers while stating that account IDs and passwords were not leaked. Bithumb said it reported the incident to Korean authorities, restricted affected accounts, operated a response center, compensated affected users, and distinguished the data exposure from later cryptocurrency losses tied to long-running credential-stuffing attempts and voice-phishing of authentication messages.