2026 IDC Frontier — IDCF Cloud East Japan Region 1 ransomware; 495 orgs affected
Data compromised
Service outage for 495 companies and local governments (company count). Customer PII/exfiltration census unpublished — recordsAffected 0. Unverified social claims of hypervisor/datastore encryption figures not company-confirmed.
Technical writeup
Verified company notices — SoftBank-owned IDC Frontier confirmed unauthorized access then a ransomware attack affecting IDCF Cloud East Japan Region 1 from about 03:40 on October 7, 2026. Second report states 495 companies and local governments that use IDCF Cloud were contacted. The region was cut off from the network and shut down; the external management console for other regions was suspended pending safety checks. Nikkei places East Japan Region 1 at Shirakawa (Fukushima). SoftBank/Kyodo confirmed Ibaraki Prefecture and Ibaraki Prefectural Police websites down; other customers (Greenwich, Medialink, Fuva Brain, UD Talk, SKE48 Mail, Net Assist) publicly blamed the IDCF outage. Social images claiming 239 hypervisors / 225 datastores encrypted / 16,600+ VM disks / 550k snapshots destroyed remain unverified. No named ransomware group, ransom demand, exfiltration census, or recovery ETA published at indexing.
Root cause
Ransomware attack on IDCF Cloud East Japan Region 1 (~03:40 Oct 7 2026); region network-isolated and shut down