SoftBank subsidiary IDC Frontier: ransomware hit IDCF Cloud East Japan Region 1 (7 Oct), affecting 495 corporate and local-government customers; customer data in four zones hard to restore without own backups
IDC Frontier (IDCF), a SoftBank Group subsidiary that runs the IDCF Cloud IaaS platform, said a third-party ransomware attack caused a disruption in East Japan Region 1 from about 3:40am JST on 7 October 2026. Its third notice (8 Oct) says 495 corporate and municipal customers were affected. Impacted zones named: tesla, henry, pascal and joule. Effects included virtual servers stopping and not restarting. IDCF isolated East Japan Region 1, stopped the management console across regions while it checked safety, and is working with an external security firm to find and block the intrusion path. For the four named zones it says customer data is difficult to retrieve or restore and that recovery currently depends on customers' own backups; it is guiding those customers to rebuild in a separate environment. Other East Japan 1 zones and other regions had no confirmed unauthorised access at the time of the notice, but customers were told to take their own backups. IDCF has reported to regulators and the Tokyo Metropolitan Police. Wire coverage (BleepingComputer, NHK, Mainichi) notes knock-on outages including Nissui logistics shipping and Ibaraki prefectural and police websites; IDCF has not itself confirmed every downstream victim in the notice. Threat-actor social posts claiming encrypted databases and hypervisors are unverified by IDCF. Primary: IDC Frontier notice 20261008001; wire: BleepingComputer.
- Product
- IDCF Cloud (East Japan Region 1 — tesla/henry/pascal/joule zones); SoftBank subsidiary IDC Frontier
- Versions
- n/a — ransomware incident; TypeS / private cloud stated out of scope in IDCF notice
- Exploited in Australia?
- unknown
- Patch to
- IDCF Cloud customers in the named East Japan 1 zones: follow IDCF guidance, rebuild from your own backups in a separate environment, and treat management-console downtime as expected until IDCF reopens it. Other IDCF regions: take fresh off-platform backups. Broader lesson: keep independent backups of cloud IaaS workloads that the provider cannot restore for you.
Primary: IDC Frontier — Notice 3: unauthorised access / disruption on part of IDCF Cloud (8 Oct 2026, Japanese) · Vendor: IDC Frontier (SoftBank subsidiary) — IDCF Cloud incident notice · BleepingComputer — Ransomware attack disrupts Japan's IDCF Cloud used by govt clients (8 Oct 2026)