Breaches · 3h ago
Keio Corporation, a major Japanese private railway operator, said a weekend ransomware attack disrupted some of its business systems. The company has not yet detailed the scope of the interruption or how long recovery will take.
The immediate hit is to the systems that keep the operation coordinated behind the scenes: ticketing, scheduling, customer support, and other business functions that help passenger service run smoothly. Even without any confirmed impact on train control, that kind of compromise can still slow the work that supports the rail network.
For transportation operators, this is the part of ransomware that matters most: a business-system outage can spill into customer-facing delays and operational friction long after the infected machines are contained. What remains unknown here is how far Keio’s disruption reached inside its own coordination layer, and whether any passenger-service effects followed.
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Japanese Railway Operators Hit with Weekend Cyber Attacks
Tokyo Metro and Keio have revealed separate cyber-attacks
Japan's Keio confirms ransomware attack disrupted business systems
Keio Corporation (Keio), a major private railway operator in Japan, said its network was hit by a ransomware attack over the weekend, disrupting some of its business systems.
Part of the PlainSec briefing for 2026-09-29