INSPECTING ARCHIVED INTELLIGENCE (OUTDATED VERSION).

Forty Thousand Customer IDs Leaked from 16 Institutions

| 2026-10-28 08:10 CRITICAL LOW DATA BREACH
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Executive Summary
AI-generated
A hacking incident at Daesung Securities has exposed the personal information of 38,490 customers, with an estimated total of 100,000 cases of data exposure reported. The leaked information includes customer name, email, address, communication ID, bank name, deposit-outcome account number, comprehensive account number, and mobile phone number, with only a portion encrypted. Experts attribute the attack to targeted hacking into the investment account opening server, citing lax security management of the external access system as a potential entry point. The incident is part of a larger leak affecting 16 financial institutions, with experts noting that the actual scope of leaks depends on how many customer information is stored in the attacked system and its connectivity to other servers.
Technical Mitigations AI-generated
• Patch the external solution program vulnerability that allowed access to the server containing customer information at Korea Savings Bank. • Implement a more robust security management system for non-face-to-face securities account opening systems, such as Daewoo Securities' service. • Monitor and block unusual IP addresses on web systems, like Daewoo Securities did after detecting unusual access.
Intelligence Metadata
Actors / Malware / CVEs / Campaigns
Target & Sectors
Global Scope financefinance
Incident Timeline
‎2026/10/28
Daesung Securities' investment account opening server was hacked, resulting in the exposure of 38,490 customers' personal and credit information.
organisation Daesung Securities
A hacking incident at Daesung Securities has exposed the personal information of 38,490 customers, with the scale of the leak approaching 100,000 cases, according to the Korea Fair Trade Commission.
victims 38,490 customers
A hacking incident at Daesung Securities has exposed the personal information of 38,490 customers, with the scale of the leak approaching 100,000 cases, according to the Korea Fair Trade Commission.
Daesung Securities announced on 28th that its investment account opening server was hacked, resulting in the exposure of 38,490 customers' personal and credit information.
organisation IP
In the future, the asset management company also confirmed that it had detected unusual access to an external internet address (IP) on its web system.
organisation Daewoo Securities
The scope of the Daewoo Securities leak is the second-largest among the financial sector hacking incidents confirmed recently.
organisation the Korea Savings Bank
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
The Korea Savings Bank was attacked through a remote vulnerability in an external solution program, which allowed access to the server containing customer information.
organisation Shinhan Bank
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
victims 40,000 customers
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
victims 25,000 customers
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
organisation the Information Protection Department
A professor from the Information Protection Department at Chonbuk National University said, "The scale of leaked information due to hacking varies depending on how much personal data is stored on the server attacked."
organisation Chonbuk National University
A professor from the Information Protection Department at Chonbuk National University said, "The scale of leaked information due to hacking varies depending on how much personal data is stored on the server attacked."
organisation Shinhan Bank's
Shinhan Bank's service that was attacked is a loan collection service exclusively for borrowers, which allows borrowers to check the loan processing status through the mobile website 'Msinhan'.
organisation the Cybersecurity Institute
Yoo Jin, a professor from the Cybersecurity Institute at Ajou University, said, "Financial institutions have been subject to very strict regulations, and their core systems have been strictly protected in accordance with regulations and rules."
organisation Ajou University
Yoo Jin, a professor from the Cybersecurity Institute at Ajou University, said, "Financial institutions have been subject to very strict regulations, and their core systems have been strictly protected in accordance with regulations and rules."
Tactical Metrics
Metrics
victims
38,490
Customers
A hacking incident at Daesung Securities has exposed the personal information of 38,490 customers, with the scale of the leak approaching 100,000 cases, according to the Korea Fair Trade Commission.
Daesung Securities announced on 28th that its investment account opening server was hacked, resulting in the exposure of 38,490 customers' personal and credit information.
Metrics
victims
40,000
Customers
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
Metrics
victims
25,000
Customers
Earlier, it was found that 40,000 customers' information was leaked from the Korea Savings Bank, while 25,000 customers' information was leaked from Shinhan Bank.
Intelligence Sources
Chosun Economy 2026-10-28