Bithumb reported that an external party infiltrated an internal employee mobile network and made off with personal data, though zero cryptocurrency assets were stated to have vanished.
The South Korean trading platform explained that the affected network operated independently from its trading engine, although it has yet to reveal the exact count of impacted individuals or if transactional deposits and services were interrupted.
This security incident happens in the middle of a wave of digital assaults targeting South Korean financial institutions, following a prior incident in February where Bithumb mistakenly distributed $40 billion worth of Bitcoin to users due to an error.
Bithumb, serving as South Korea’s number two cryptocurrency exchange, announced on Wednesday morning that an unauthorized individual penetrated the internal mobile infrastructure utilized by staff for internal operations and communication, resulting in the theft of personal details.
Based on afternoon market reports in Asia, there were no indications of missing digital assets. Bithumb holds its position as the country’s second-biggest marketplace by transaction volume.
As reported by local publications, the platform discovered the breach on Tuesday and promptly notified both the Korea Internet & Security Agency alongside the Personal Information Protection Commission. The company informed Yonhap that it is currently investigating the full extent of the issue, “including the likelihood that user details were compromised.”
The company noted that the compromised infrastructure operates completely apart from its exchange engine, meaning that “client digital assets remain safe from unauthorized entry via this security event.” Management has omitted details regarding whether deposit and withdrawal operations experienced downtime or how many users had their information exposed.
The Financial Supervisory Service identified Bithumb as one of three financial institutions under review on Wednesday. Concurrently, Daishin Securities acknowledged that private and financial details belonging to 38,490 clients were compromised in an external security breach, while Mirae Asset Global Investments reported successfully stopping suspicious entry attempts on specific web portals without jeopardizing client data.
FSS Governor Lee Chan-jin addressed heads of bank holding companies during a gathering, stating, “I am aware that principal financial investment organizations suffered widespread cyber intrusions yesterday.” Earlier in the month, he disclosed that digital incursions had already targeted 16 financial entities in South Korea as of October 14.
For Bithumb, this marks the second time this year that its operational oversight has faced scrutiny.
Back in February, the platform accidentally deposited 620,000 BTC—valued in excess of $40 billion at the period—into user balances instead of distributing 620,000 won. Chief Executive Officer Lee Jae-won attributed the mistake to inadequate internal oversight at that time, stating that the company was “deeply conscious of the flaws in our internal management framework.”
Originally published at https://www.coindesk.com/tech/2026/10/28/bithumb-hacked-through-employee-system-as-south-korean-financial-firms-face-cyberattacks.
