Business SaaS and e-mail
Chumon-kun
Chumon-kun (run by Matsuzawa Shoten Inc.) was hit in 1 recorded cybersecurity incident. The latest was disclosed on 2026-05-09.
About the service
- Run by
- Matsuzawa Shoten Inc.
- Category
- Business SaaS and e-mail
- For
- Businesses
Incident history
Disclosed 2026-05-09Updated 2026-10-22Tokyo[Contained][Severity: Critical][Breached][Critical]
Matsuzawa Shoten: ransomware attack[Ransomware][Service outage]Organizations 1