Coinone said an external attacker accessed MetaM’s server at about 4 a.m. on Nov. 12, potentially exposing personal information submitted during customer consultations. The data may have included names, email addresses, phone numbers, dates of birth, account numbers, passwords, resident registration numbers, ID card issue dates, home addresses, wallet addresses and transaction IDs. Coinone detected the incident at 9:20 a.m. and said its member accounts, trading system and digital-asset wallet system operate separately from MetaM’s server, with no confirmed signs of direct intrusion. The exchange blocked the attack IP address, suspended customer-center access, moved support to email and reported the incident to South Korean authorities. Coinone and MetaM are investigating the circumstances and warned customers about potential secondary scams, including voice phishing. The incident adds to security concerns following breaches involving GoPax, Bithumb, Pravang and Flybit; regulators have permitted exchanges to block deposits and withdrawals proactively when hacking is suspected, while the Financial Supervisory Service planned a Nov. 19 meeting with industry chief information security officers.