Notice Regarding Cybersecurity Incident [Report 3]
UCHIYAMA HOLDINGS Co.,Ltd. (the filing company)
The company's IT environment, internal network, related systems and some employee information stored on the internal network
Company response
Normal operations will resume on or after 20 April 2026
Investigations and monitoring by an external cybersecurity specialist and specialist organizations are ongoing
24-hour, 365-day monitoring using endpoint detection and response (EDR). Review of the network configuration and strengthening of authentication processes. Renewed information security training for all officers and employees.
The impact on financial results is still being assessed. If a material impact on future financial results is identified, it will be disclosed promptly
Related procedures
Personal Information Protection Commission
Individuals whose information has been confirmed to have been leaked, as well as those whose information may have been leaked, will be notified in sequence. Relevant parties affected will be contacted as appropriate. Monitoring by an external cybersecurity specialist will continue. Additional countermeasure costs and related losses may arise.
If a material impact on financial results is identified, it will be disclosed promptly
| Item | Details |
|---|---|
| Event name | Notice Regarding Cybersecurity Incident [Report 3] |
| Date of occurrence | The date on which unusual activity was detected in the morning and servers and endpoints suspected of being infected with ransomware were isolated: Saturday, 7 March 2026 |
| Date recognized / date notice received | 7 March 2026 |
| Subject Entity | UCHIYAMA HOLDINGS Co.,Ltd. (the filing company) |
| Target Locations / Products | The company's IT environment, internal network, related systems and some employee information stored on the internal network |
| Impact on Earnings Forecast | The impact on financial results is still being assessed. If a material impact on future financial results is identified, it will be disclosed promptly |
| Court or authority | Personal Information Protection Commission |
| Scheduled resumption date | Normal operations will resume on or after 20 April 2026 |
| Investigation structure | Investigations and monitoring by an external cybersecurity specialist and specialist organizations are ongoing |
| Measures to prevent recurrence | 24-hour, 365-day monitoring using endpoint detection and response (EDR). Review of the network configuration and strengthening of authentication processes. Renewed information security training for all officers and employees. |
| Outlook | Individuals whose information has been confirmed to have been leaked, as well as those whose information may have been leaked, will be notified in sequence. Relevant parties affected will be contacted as appropriate. Monitoring by an external cybersecurity specialist will continue. Additional countermeasure costs and related losses may arise. |
| Planned follow-up disclosure | If a material impact on financial results is identified, it will be disclosed promptly |
Items this document does not state (13)
These are items the company does not state in this document. We do not leave them blank, nor fill them in from other sources or by inference.
The reasons the company gives
The company's own explanation, not something inferred from the numbers.A system outage occurred as a result of a ransomware infection. The company explained that it is investigating and addressing the possibility of an information leak, system recovery costs, investigation costs and related damages in cooperation with an external cybersecurity specialist.