Japan's Keio confirms ransomware attack disrupted business systems

September 28, 2026 · BleepingComputer · Severity: CRITICAL

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.

Key Takeaways

According to BleepingComputer, this development warrants attention from teams monitoring the evolving threat landscape.
Given the CRITICAL severity rating, organizations should prioritize remediation in their vulnerability management workflow.
Security teams should review their exposure and implement appropriate defensive controls.