IDCF Cloud Ransomware Attack Hits 495 Clients, ITmedia Reports

A third-party ransomware attack on SoftBank subsidiary IDC Frontier’s cloud infrastructure has disrupted 495 corporate and municipal clients across Japan, ITmedia reported on Oct. 7, 2026.

Unauthorized Access Halts East Japan Region Systems

The disruption began at approximately 3:40 a.m. on Oct. 7, 2026, when unauthorized access by a third party targeted systems within the Eastern Japan Region 1 data center located in Shirakawa, Fukushima Prefecture. To verify safety following the breach, IDC Frontier also halted management consoles allowing external user access across other operational regions.

Corporate and Municipal Services Fall Offline

Greenwich, a Tokyo-based e-commerce service provider, reported that its Rakuraku Zaiko inventory tool and Rakuraku Saian Koushin service were forced offline, alongside partial disruptions to the Ultra ASP store management utility. Hoover Brain stated that its PC operation log management service and security product control screens became inaccessible, while Shamrock Records noted that its voice recognition application UD Talk lost editing, public talk viewing, and management tool capabilities. Movable Type Cloud also suffered server access failures affecting management screens and public sites across 31 servers in the primary eastern region.

Non-IT entities experienced disruptions as well, including the Japan Basketball Association, Radio Kansai, capsule hotel chain Anshin Oyado, and karaoke operator Karaoke Pasela, though those organizations did not explicitly name the cloud provider. Municipalities including Ibaraki Prefecture and Kodaira City, alongside J.League clubs and Tobu Zoo, reported inaccessible websites on the morning of Oct. 7, 2026. JRA System Services confirmed that its overseas horse racing information site JRA-VAN World suffered a total outage starting at 3:40 a.m.

Companies Report Conflicting Prospects for Data Recovery

Affected companies reported divergent outlooks regarding data retrieval. The illustration commission service SKIMA initially considered data recovery extremely difficult, but later confirmed that salvageable data remained and stated it was working to restore systems. Conversely, the team behind the UD Talk app stated on X that IDC Frontier informed them data restoration is difficult, prompting developers to plan an environment rebuild on an alternative cloud foundation using local backups.