Bithumb among three South Korean financial firms reporting data breaches

Three South Korean financial firms disclosed data breaches on Wednesday, October 28, and one of them runs a crypto exchange. Bithumb, Daishin Securities and Mirae Asset Global Investments each reported hacking incidents on the same day, according to Yonhap News Agency.

Bithumb said its in-house mobile system had been compromised and that personal information had leaked, Yonhap reported. The exchange’s position is that crypto holdings were never in the line of fire.

What each firm disclosed

According to the exchange, the intrusion hit an internal mobile groupware system used by employees. Groupware is the office plumbing: messaging, scheduling and internal documents, not the engine that matches buy and sell orders.

Bithumb said that system has no connection to its trading operations. The company stated that its internal systems are kept separate from its trading platforms, so virtual assets are not at risk.

Still, the break room had personal information in it. Bithumb is investigating the full scope of the incident, including whether any customer data was compromised.

The exchange notified the Korea Internet & Security Agency and the Personal Information Protection Commission on the same day it discovered the breach.

Daishin Securities had a more concrete, and more uncomfortable, set of numbers to share. The brokerage confirmed that approximately 38,490 customers were affected by unauthorized access it detected on October 17.

The exposed data covered a wide range. It included names, email addresses, physical addresses, bank account numbers and mobile phone numbers.

Daishin said it has notified affected customers. The firm is also rolling out emergency measures to prevent further damage.

Mirae Asset Global Investments reported a hacking incident that hit some of its business systems. Citing the Financial Supervisory Service, reports indicated minimal risk to customer data and no significant financial losses.

Of the three, Mirae’s disclosure reads as the mildest. The firm said no broad customer data was compromised.

A month of breaches and a PHP warning

Wednesday’s disclosures did not come out of nowhere. Earlier in October, at least 16 South Korean financial institutions were hit by cyberattacks.

Those earlier incidents have been tied to an estimated 100,000 reported data leak cases. Add Daishin’s roughly 38,490 affected customers and the count of exposed records across the sector keeps climbing.

Separately, the Science Ministry in Seoul and the Korea Internet & Security Agency urged website operators to check their systems for PHP flaws. PHP is a widely used programming language that powers a large share of websites behind the scenes.

Vulnerabilities tied to PHP have been exploited in these attacks, according to the research findings.

The Financial Supervisory Service has stepped up scrutiny and inspections of financial firms, urging them to fix weak spots. The regulator also stressed the need for stronger IT security as cyber threats evolve, possibly driven by artificial intelligence.

What this means for Bithumb users and Korean finance

For Bithumb customers, the immediate question is simple: is my crypto safe? The exchange says yes, pointing to the wall between its employee systems and its trading platforms.

The open question is the personal information. Until Bithumb finishes its investigation, users cannot know whether their own details were part of the leak.

The things to watch next are the results of Bithumb’s internal investigation and whether customer data turns out to be involved. Also worth tracking: whether the PHP warning from the Science Ministry and the Korea Internet & Security Agency slows the run of attacks, or whether more disclosures follow before the month is out.