South Korean cryptocurrency exchange Bithumb said an intrusion into its internal mobile groupware system exposed personal information connected to 844 customers and 715 employees. The breach occurred on Oct. 27, when an outside party gained access to Daou Office, a workplace communications and information-sharing platform used by employees. Bithumb detected the incident and notified financial authorities, the Korea Internet & Security Agency and the Personal Information Protection Commission the same day.
Bithumb said 6,444 customers were affected by the incident, but information for 5,600 of them remained protected in encrypted files that could not be accessed externally. The exposed information varied by customer and included names, mobile phone numbers, email addresses, resident registration numbers, driver’s license numbers, account numbers and identification-card copies. The exchange planned to notify affected customers individually and provide a way for them to check the status of their information.
The compromised groupware platform operates separately from Bithumb’s customer trading services and core systems. Bithumb and financial authorities said they had not found evidence that customer virtual assets, wallet addresses or information usable for unauthorized payments or asset transfers had been exposed. The exchange was still examining whether customer assets or deposits had been stolen and whether the breach reached other parts of its systems.
Bithumb chief executive Lee Jae-won apologized to customers and said the company would pursue relief and compensation if secondary harm were confirmed. Financial regulators began on-site inspections, coordinated information sharing and an investigation into the cause of the intrusion. They also said consumer-protection measures, including full compensation where losses occurred, would be considered if victims suffered damage.
The incident emerged during a wider series of cyberattacks against South Korea’s financial sector. Regulators said breaches had been identified at 16 financial companies and institutions by Oct. 14, involving about 100,000 customer-information records; later disclosures involving Bithumb, Daishin Securities, Mirae Asset Global Investments and Mirae Asset Life Insurance raised the publicly identified total to at least 20 companies. Daishin separately disclosed compromised personal and credit information involving 38,490 customers, while Mirae Asset said suspicious access to some web systems had been blocked without evidence that investor information was affected.
Financial authorities said they would review security practices across virtual-asset businesses and strengthen protections for sectors not covered by the same electronic-financial-transaction rules as banks. Bithumb’s investigation and the regulators’ inspections were continuing, leaving the final scope of the customer-data exposure and any resulting harm unresolved.