Keio Group Reports Ransomware Attack Disrupting Some Business Systems
Summary
Keio confirmed a ransomware attack on group servers on September 26, 2026. Some group-company business systems are affected; railway operations are unaffected, and the company has not confirmed information leakage.
Key points
- Keio confirmed a ransomware attack on group servers in the early hours of September 26, 2026.
- Business systems at some group companies have been disrupted.
- Railway operations are not affected.
- Keio has not confirmed information leakage and is investigating the potential impact.
- The company isolated network connections to limit further damage and is investigating the attack with external specialists.
- Keio reported the incident to police.
Article Details
- Victim Organization
- 京王電鉄株式会社
- Incident Type
- Ransomware attack causing a system outage
- Incident Date
- 2026-09-26
- Disclosure Date
- 2026-09-26
- Operational Impact
- Sales systems at some group companies were disrupted. Railway operations were unaffected at the time of disclosure.
- Ransom Or Extortion
- No ransom demand or extortion activity was reported.
- Claim Status
- confirmed