Ransomware victim disclosure
← All victimsNostrum
Claimed by thegentlemen · listed 15 days ago
Status timeline
- Listed
May 6, 2026
- Data leaked
At a glance
- Group
- thegentlemen
- Status
- Data leaked
- Country
- JP
- Sector
- Not Found
- Listed on leak site
- May 6, 2026
About the victim
AI dossier — public-source company profileNostrum Corporation (株式会社ノストラム) is a Tokyo-based Japanese technology company founded in 1991. The company specialises in smartphone application development (iOS and Android), web system development and website construction, hardware board design/manufacturing, and e-learning software. Its flagship self-developed product is SMART SPI, an online job-aptitude-test preparation platform used by university students and job seekers across Japan.
- Industry
- IT Services & Software Development (Smartphone Apps, Web Systems, Hardware Solutions)
- Address
- Japan (Tokyo inferred from phone prefix 03-3512-0871); full street address not stated on public site
- Founded
- 1991
Attack summary
Severity: high — Data has been published (data_published status) and the victim's own site confirms a ransomware infection causing service disruption. The e-learning platform likely holds PII of student and job-seeker users; prior development work includes medical, pharmaceutical, and financial sector systems suggesting sensitive client data may be present. Confirmed exfiltration and operational disruption together warrant a high rating.The group 'thegentlemen' claims a ransomware attack that infected Nostrum's servers; the company's own website (dated 2026-05-08) confirms a ransomware infection causing suspension of its learning-support service. The disclosure status is 'data_published', indicating the attackers claim to have exfiltrated and published data, though no specific data size or ransom amount was stated.
Data the group says was taken
AI dossier — extracted from the leak post- Company internal systems data
- Customer/user data from e-learning platform (SMART SPI)
- Web and mobile application project files
- Business operational data
What the group claims
nostrum.co.jp Nostrum Corporation, based in Japan, was founded in 1991 and specializes in smartphone app development, web system development, and website construction. The company is represented by Ryoichi Jono and is registered on the J-GoodTech platform as a verified Japanese technology business. One of their flagship self-developed products is a job aptitude test preparation tool — a simulation platform replicating real SPI, TG-WEB, and similar employment exam interfaces used by major Japanese companies
Sources
- Victim sitenostrum.co.jp
Source
Indexed 15 days agoThis page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.
