Keio: ransomware attack on the group

Group servers were hit by ransomware early on 26 September, disrupting Keio Plaza Hotel reservations and cashless payments at Keio Store; trains were not affected. On 15 October Qilin claimed the attack and published 27 images it says are internal documents. In its October 21 third report, Keio said external experts reported publication of information claimed stolen by the attacker. It notified the Personal Information Protection Commission because personal data might be involved; content and scope remained under investigation.