Explanation of the cyberattack incident affecting part of the Company’s information systems

Company code:5434
No:1
Subject:
Explanation of the cyberattack incident affecting part of the Company's information systems
Description:
1.Date of occurrence of the event:2025/10/23
2.Cause of occurrence:
On October 23, 2025, the company detected unauthorized access by unidentified hackers who infiltrated part of its servers and encrypted data, resulting in temporary system downtime.
3.Handling procedure:
The company immediately activated its cybersecurity defense and recovery mechanisms, engaged external cybersecurity firms and experts to assist with investigation and remediation, and filed a report with the Ministry of Justice Investigation Bureau. Notifications to the relevant competent authorities have been made, or will be made, in accordance with applicable procedures.
4.Anticipated possible loss or impact:
The company is actively working with technical experts to investigate and restore the affected systems. Based on
the current assessment, the incident has no significant impact on the company's operations, information security, or personal data.
5.Amount of insurance claims that might be obtained: Not applicable.
6.Improvement status and future countermeasures:
The company will continue to enhance the security management of its network and information infrastructure
to ensure data protection and system resilience.
7.Any other matters that need to be specified: None.