Tottori Prefecture: the main server of its environmental radiation monitoring system was hit by ransomware and stopped; the backup server was unaffected

1. 2026-09-03

   The prefecture announced a cyberattack on its environmental radiation monitoring system, which collects and watches measurement data such as dose rates from monitoring posts. The main monitoring station (main server) in the prefectural offices was hit by ransomware, its electronic files were encrypted, and the system stopped. [1] [2]

The backup monitoring station (sub-server) at a remote site was not affected, radiation monitoring continued and monitoring was not impaired. The system runs on a monitoring-only network that is separate from the prefecture's administrative network. It is a system for publishing data and holds no personal information. [1] [2]