Three of Korea's Five Big Banks Got Hacked. I Haven't Changed a Thing.
Three of Korea’s five largest commercial banks have lost customer data in hacking attacks, and this time the leak included resident registration numbers, Korea’s national ID number. That part shocked me. Leaks are common here, and I have mostly stopped reacting to them. But I also have to be honest: since the news broke, I have not changed a single setting in my banking or brokerage apps.
What Happened
According to local reports (in Korean), Shinhan, KB Kookmin and Hana Bank all had customer information taken. The attacks are believed to have run from September 27 to 29. For some customers, the leaked data included names, resident registration numbers and phone numbers. Information about bank employees was also taken.
It did not stop at the big banks. Over the following days, Korean press reported one leak after another:
| Where | What was reported |
|---|---|
| Welcome Savings Bank, Yegaram Savings Bank, Hyundai Capital | Personal data leaks at these second-tier lenders |
| KEPCO (Korea Electric Power) | Names, departments and phone numbers of about 24,000 employees exposed on an outside web page |
| Seoul Cyber University | Data on students, graduates, staff and job applicants leaked |
| Yoido Full Gospel Church and SaRang Church | Hit by cyberattacks; data on up to 1 million members may have leaked |
| Malgeun Soft (online education sites) | Data on about 5,000 union members at Kia’s Gwangmyeong plant and about 40,000 users of education ministry-linked bodies (report (in Korean), report (in Korean)) |
Why Nobody Around Me Said Much
A reader outside Korea might expect people here to be angry or scared. I did not hear much reaction at all. Korea has had many personal data leaks, one after another. After enough of them, a new one just feels ordinary.
What made this one different for me was the resident registration number. In the leaks I remember, it was mostly phone numbers. A leaked phone number means more spam calls. Seeing the national ID number on the list, from three major banks at once, was a shock in a way the earlier leaks were not.
The AI Part
The story got bigger when experts said AI was likely used in the recent attacks. Korean business press reported (in Korean) that the bank hacks used ARTEX, a Chinese AI-based penetration testing tool. According to the reports, one AI agent plans the next move, another agent tries the attack, the results are analyzed and shared, and the planning agent makes a new plan. Then it repeats.
Some AI-based hacking tools have been made open source, and some say this has made hacking easier to start. Among security experts, the phrase going around (in Korean) is that AI has made hacking available to the masses.
There are limits to what anyone knows. How much AI was actually used is hard to confirm. As reported, an attacker’s use of generative AI does not show up in the victim’s data logs. And financial regulators concluded (in Korean) that the AI did not attack without people involved.
For me, the AI part did not bring a new feeling. It made my worry about banking through apps sharper. Almost all my money moves through apps. I do not visit a branch. The news made me ask, more seriously than before, whether doing everything without ever meeting anyone at a bank is really safe.
What I Did About It
Nothing, so far. There are two reasons.
I don’t know how. I have no idea what to change or how to make my accounts safer, so everything is the same as before.
The app I use was not on the list. I have not seen any report that it leaked, so I did not check it separately.
I suspect many people here are in the same place: worried enough to notice, not sure enough to act. Now that I write it down, the second reason looks weaker than it felt. The list above kept growing for days after the first report. Whether “no news yet” is a good enough reason to do nothing is a question I have not answered.