Notification of Group Company's Cyber Incident in U.S.

2026-5-7

Accretech America Inc. (hereinafter “ACCT America”), one of the group companies of Tokyo Seimitsu Co., Ltd. (hereinafter “the Company”), has confirmed that a ransomware attack occurred on some of its systems on May 4th, 2026 (hereinafter “the Incident”).

 

Upon discovering this incident, ACCT America has taken immediate measures, such as shutting down its network to prevent further damage, and has suspended the use of various systems, and the Company made necessary reports to the administrative authorities.

 

In response to this incident, under the direction of the Company’s Cyber Incident Response Team (ACCT-CSIRT), the Company has begun an investigation in collaboration with external security experts to determine the cause and assess the extent of the damage. If future investigations confirm that customer or employee information has been affected, we will promptly contact those individuals directly and provide guidance on necessary measures. We will continue to proceed with the investigation in cooperation with external security experts.

 

At this time, this incident has not affected other companies in our group, including the Company.

 

We deeply apologize to our customers, business partners, and other stakeholders for any concern this incident may cause.

The Company group has been implementing information security measures to date. Taking this situation very seriously, we are committed to further strengthening our management system and implementing action in cooperation with relevant organizations and agencies. Your understanding and cooperation would be highly appreciated.

 

If any new facts requiring disclosure come to light in the future, we will announce them promptly.