South Korean cryptocurrency exchange Bithumb has confirmed a personal data leak after attackers gained unauthorized access to its internal mobile system, an incident that has sharpened concerns about cybersecurity across the country's financial sector.

The exchange discovered the breach on October 27, 2026, and launched an investigation into the compromised information. According to reports published Wednesday, Bithumb is examining whether hackers accessed customer data in addition to internal employee information.

Bithumb Probes Internal System Breach

The cyberattack targeted Bithumb's internal mobile groupware system, which employees use for workplace communication and information sharing. Hackers reportedly obtained unauthorized access to the platform, exposing personal information stored within it.

Bithumb reported the incident to the Korea Internet & Security Agency and the Personal Information Protection Commission after discovering the intrusion.

The exchange is assessing the scope of the leak and identifying the records affected. Initial findings point to employee-related information, though investigators have not ruled out that customer data was involved.

Bithumb stressed that its internal communication platform operates separately from its cryptocurrency trading infrastructure, meaning attackers could not reach customer digital assets through the compromised system, the company said. That separation is the central detail for exchange users: while the compromised system sat outside the platform that holds and processes customer funds, personal information exposed through corporate systems can still carry downstream consequences, as leaked records are commonly repurposed in phishing and impersonation attempts.

South Korea Faces Wider Financial Cybersecurity Pressure

The incident comes amid a broader wave of cyberattacks targeting South Korean financial institutions. Reuters reported on October 28 that three financial companies, including Bithumb, had disclosed security breaches. The other affected institutions were Daishin Securities and Mirae Asset Global Investments.

Daishin Securities confirmed that hackers exposed the personal and credit information of 38,490 customers. Mirae Asset Global Investments reported suspicious external access and has launched an investigation into its systems.

The range of affected firms — spanning a cryptocurrency exchange as well as securities and asset management companies — shows the pressure extends across South Korea's financial industry rather than being confined to crypto platforms. South Korean financial authorities have intensified scrutiny of cybersecurity practices in response. Earlier in October, officials identified cyberattacks affecting 16 financial companies, underscoring growing risks across the industry.

Exchange Security Remains Under Scrutiny

The breach highlights the importance of protecting internal business systems even when they operate independently of cryptocurrency trading platforms. While Bithumb maintains that customer digital assets were inaccessible through the affected system, uncertainty over the leaked information remains.

The exchange has yet to disclose the full scale of the breach or confirm exactly which personal records were compromised. Investigators continue to assess the intrusion as authorities monitor cybersecurity risks across South Korea's financial sector. The open questions to follow are whether customer records were ultimately involved, how many individuals were affected, and what further steps regulators take as the month's cluster of financial-sector disclosures continues to develop.