KB Kookmin Bank has expanded the confirmed number of people affected by a personal data breach from 119 to 2,210 after a renewed review with regulators and other relevant agencies. The additional group comprises 1,631 customers and 460 current or former employees, bringing 2,091 newly identified people into the scope of an incident first disclosed earlier this month.
The bank said the increase did not result from a new cyberattack. It emerged as investigators rechecked system data and processing records connected to the original intrusion, which was reported to have involved a mobile work-support system used by employees. The revision shows how the full reach of an intrusion can remain unclear even after an institution makes an initial disclosure.
The information exposed varied by customer. Investigators found that affected records could include names, birth dates, addresses, contact details, email addresses, occupations and annual income, as well as encrypted resident registration numbers. Some records also contained financial information such as deposit balances, account numbers, loan transaction details, overdue credit-card principal, credit ratings and whether a customer had applied for a debt workout.
Records involving employees included staff numbers, names, mobile phone numbers, email addresses, branch or department affiliations and dates connected to personnel matters. KB Kookmin Bank said it would notify affected people individually, provide guidance intended to reduce secondary harm and implement measures to prevent a recurrence.
- Newly identified bank customers
- 1,631
- Newly identified current or former employees
- 460
- Nature of the bank update
- Expanded findings from the existing incident, not a new attack
The expanded count heightens the risk of targeted fraud because identity details and account-related information may be combined to make deceptive messages or calls appear credible. Customers receiving unexpected requests should independently verify the sender through an official bank channel rather than using contact details or links included in a message. The evidence does not establish that every listed category of data was exposed for every affected person.
Financial records raise follow-on fraud concerns
A separate incident at Mirae Asset Life Insurance has widened scrutiny beyond banking. The insurer said it detected unusual activity in some systems, began an investigation with an external specialist and confirmed a personal data leak early the following morning. It blocked internet protocol addresses associated with the attack and activated an emergency response system.
Reports said hackers accessed and viewed about 41 files, but the company was still determining how many contained customer information, how many people were affected, which data fields were involved and whether information had been transferred outside its systems. Mirae Asset Life advised customers not to respond to suspicious text messages, calls or emails from unidentified sources and apologized for the incident.
Regulators examine the insurerโs breach
The Financial Supervisory Service began an urgent on-site inspection of the insurer to establish the scale and route of the breach. Investigators must now clarify the affected population at Mirae Asset Life while checking whether containment measures are holding. For KB Kookmin Bank, attention will center on customer notification, protection against follow-on fraud and whether the expanded review has fully identified the records compromised in the original attack.