Nostrum
bd_ff261fee6341fc80 · schema v1 · pii pii-v1
Full breach record for Nostrum →Threat-actor claim — not a regulatory filing
This row is a claim by the ransomware group Thegentlemen on its public extortion blog. It has not been validated by the victim or any regulator. Treat attribution and counts as the threat actor's assertion until a regulatory filing or victim disclosure corroborates them.
Source: Ransomware.live
Post text · scraped from the leak site
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
Source provenance
- Source URL
- https://www.ransomware.live/
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
- Filed at
- Apr 27, 2026
- Raw hash
- f056e45cdb72f318464b2261d3777eaae58ed1d8a38fbd72aad656135ca7ed06
Reporting entity
- Name
- thegentlemen
Victim entity
- Name
- Nostrumnorm: nostrum
- Domain
- nostrum.co.jp
What this source establishes
- Source ceiling
- A leak-site claim can't tell us: discovery date · materiality · notification · affected count · confirmed data types · compliance clock. These stay blank until a regulatory filing or victim disclosure lands.
- Attack vector
- Ransomware· thegentlemen
- Threat actor
- ThegentlemenExternalFinancial
Compliance
- Compliance flags
- — (clock not assessable for this source)
Extraction provenance
- Status
- No extraction artifact recorded for this disclosure.