Bithumb says intruder accessed employee mobile system and took personal data; no crypto funds reported lost

Bithumb, the second-largest cryptocurrency exchange in South Korea by trading volume, said an outside party broke into the internal mobile system that its staff use for work and messaging, and that personal information was taken. As of Asian afternoon hours on Wednesday, no loss of crypto funds had been reported.

According to Korean media, the exchange detected the intrusion on Tuesday and notified the Korea Internet & Security Agency and the Personal Information Protection Commission. It told Yonhap that it was still analyzing the exact scope of the incident, including whether member information was involved. Bithumb has not said how many people's data was exposed, nor whether deposits or withdrawals were affected.

The company stated that the compromised system operates separately from its trading platform, so customer virtual assets cannot be accessed through this breach.

Bithumb was one of three financial firms that the Financial Supervisory Service said it was assessing on Wednesday. Daishin Securities reported that personal and credit information belonging to 38,490 of its customers leaked in an external attack. Mirae Asset Global Investments said it blocked abnormal access to some of its web systems and that investor information was not affected.

FSS Governor Lee Chan-jin told a meeting with bank holding company chairs that major financial investment companies had experienced hacking incidents overall the previous day. Earlier this month he said cyberattacks had hit 16 South Korean financial firms as of Oct. 14.

The episode is the second blow to Bithumb's internal controls this year. In February, the exchange mistakenly credited customers with 620,000 BTC, worth more than $40 billion at the time, rather than 620,000 won. CEO Lee Jae-won attributed that error to weak internal controls, saying the exchange was acutely aware of the deficiency in its internal system control.