Keio Plaza Hotel
Tokyo hotel chain owned by Keio Corporation.
Keio Plaza Hotel's servers were hit in September, and the Qilin ransomware group posted files belonging to owner Keio Corporation on 15 October, without showing whether those files came from the hotel systems.
Last refreshed: 22 October 2026 · Appears in 1 active topic
What did the ransomware attack disrupt at Keio Plaza Hotel?
Timeline for Keio Plaza Hotel
Mentioned in: SiteGuard hit; Qilin posts Keio files
Cybersecurity: Threats and DefencesBackground
Keio Plaza Hotel is a Tokyo hotel chain owned by Keio Corporation. Its servers were hit in September 2026, placing the hotel operation within a wider cyber incident affecting the corporate group.
On 15 October, the Qilin ransomware group posted files belonging to Keio Corporation. The post followed an emergency alert from JPCERT/CC about attackers exploiting the SiteGuard web firewall. No published link in this account makes SiteGuard the route into Keio's systems. It also remains unclear whether the posted files came from the hotel servers, another part of Keio Corporation or both.
The public account therefore establishes an affected hotel server estate and a later leak-site claim against its owner. It does not identify which hotel functions failed, which records were taken or how the attacker first gained access.
What is Keio Plaza Hotel?
When was Keio Plaza Hotel attacked by ransomware?
What did the Keio Plaza Hotel cyberattack disrupt?
Did Keio Plaza Hotel confirm a customer data leak?
Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Updated 22 October 2026. Editorial standards.