News ReleaseNotice Regarding Unauthorized Use of Our Email Server and the Transmission of Suspicious Emails
TOKYO, JAPAN, 10 01, 2026
We have recently confirmed that our email server was unauthorizedly accessed and misused by a third party, resulting in suspicious emails in English being sent externally between approximately 3:00 p.m. on September 25, 2026 JST, and 5:15 p.m. on September 27, 2026 JST.
If you received an unsolicited or suspicious English email during this period, please do not reply to it, access any URLs contained in the message, open any attachments, make any payments, or enter any personal information. Please delete the email.
At this time, we have confirmed that there has been no leakage of personal or other information as a result of this incident, no unauthorized access to or alteration of data within our data center, and no malware infection.
1. Incident Overview
| Period | Approximately 3:00 p.m. on Friday, September 25, 2026 to approximately 5:15 p.m. on Sunday, September 27, 2026 JST |
| Affected system | Our email server |
| Estimated number of recipients | Approximately 700,000 emails (estimated) |
| Recipients | The vast majority of the emails were sent to overseas email addresses, and a limited number of deliveries to recipients within Japan have also been confirmed. |
2. Suspicious Emails
In addition, some of the suspicious emails that have been identified were found to have spoofed sender addresses, making them appear as though they originated from third-party email accounts. Therefore, it should be noted that it may not always be possible to determine whether an email is related to this incident based solely on the sender's address.
In addition, some of the identified suspicious emails were spoofed so that the displayed sender address appeared to belong to a third party. Therefore, it may not always be possible to determine whether an email is related to this incident based solely on the displayed sender address.
3. Information Leakage and Related Impact
At this time, we have confirmed that there has been no leakage of personal or other information as a result of this incident, no unauthorized access to or alteration of data within our data center, and no malware infection.
4. Response and Preventive Measures
After becoming aware of the incident, on Sunday, September 27, we implemented measures including changes to our email server settings and communication restrictions to prevent further unauthorized transmission of emails.
We will continue to investigate the cause of the incident and implement permanent measures to prevent the unauthorized use of our email server from recurring.
We sincerely apologize for the concern and inconvenience caused to those who received these emails and to all other parties affected by the unauthorized use of our email server.
