Japanese telecom provider TeleNet hit by ransomware amid broader Japan cyber attacks

Japan TeleNet Co., Ltd. disclosed that a ransomware intrusion encrypted files on its internal servers. Forensic analysis found no evidence that attackers transferred data outside the network, and there was no confirmed leakage of personal information. The breach involved personal records from its CSS, BPO, client, and employee databases, affecting tens of thousands of individuals. In response, TeleNet isolated its network, re‑engineered firewall rules, re‑imaged workstations, and implemented multi‑factor authentication, endpoint detection and response, and continuous security monitoring.

At the same time, Nichirei Corp., a Japanese frozen‑food supplier and logistics firm, suffered a separate ransomware attack that disrupted shipping for roughly 5,000 customers. The ransomware group RansomHouse claimed responsibility and released a subset of stolen personal data. Both incidents illustrate a growing wave of ransomware targeting Japanese organizations, prompting heightened security measures across the sector.