Notification of Ransomware Incident

Company Name: Eisai Co., Ltd. 
Representative: Haruo Naito 
Representative Corporate Officer and CEO 
(Code 4523 Tokyo Stock Exchange Prime Market)
Inquiries: Sayoko Sasaki
Vice President,
Corporate Communications
Phone +81-3-3817-5120  


Eisai Co., Ltd. announced today that the Eisai Group became aware of a ransomware incident that encrypted some of the Group’s servers. In response to this case, Eisai Group immediately established a company-wide task force, and is working on recovery efforts with the advice of external experts and undertaking measures to understand the scope of the incident. Additionally, Eisai Group has consulted with law enforcement.


Whilst it is expected to take some time to gauge the full extent of the incident, the information below further details what is known at this time. We deeply apologize for any inconvenience and worry this may have caused to our partners and stakeholders.


1. Background

A ransomware incident that encrypted some of Eisai Group’s servers was detected late night on Saturday, June 3, Japan time. We immediately implemented our incident response plan and launched an investigation with the aid of our cybersecurity partners. A company-wide task force was convened to rapidly work on response procedures.


2. Status and Future Response

Certain systems both in and outside of Japan, including logistics systems, have been taken offline as a result of the incident and our ongoing response process. Our corporate websites and email systems are operational at this time. The possibility of data leakage is currently under investigation.

Currently, Eisai Group is working closely with external experts and law enforcement in an effort to protect its systems and to make a successful recovery. We will continue to work to minimize any inconvenience to our partners and stakeholders.


Any potential impact of this incident on the consolidated earnings forecast of this fiscal year is currently under careful examination. If determined that revisions are necessary, an announcement will be made as soon as possible.


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Public Relations Department: +81-(0)3-3817-5120