> JapanHacked_
[Contained][Severity: Critical][Ransomware][Intrusion]

Nippon Medical School Musashi Kosugi Hospital: ransomware attack

Attackers exploited a medical-device maintenance VPN on January 26 and stole nurse-call server data on January 29. A failure revealed the attack on February 9; disclosure followed February 13. About 130,000 patient and 1,700 staff/clinical-student records leaked and were published. Nurse-call functions recovered and care continued. No intrusion into core electronic-record or billing systems, or leakage of clinical records, was found.

Disclosed

2026-02-13

Organizations involved

1

Leaked or at risk

130K

130,000

Downtime

Unknown

Timeline

  1. Started 2026-01-26
  2. Detected 2026-02-09
  3. Disclosed 2026-02-13
  4. 18 days

Attack or cause

Method
[Ransomware][Intrusion]
Impact
[Data leak][Service outage]
Entry point
VPN device

Data exposed or at risk

[Name][Postal address][Phone number][Date of birth][Gender][Employment][Education]

Organizations involved

Open in organization search

Sources

  1. [1][Official]当院へのサイバー攻撃による個人情報漏洩に関するご報告とお詫び（第5報）Nippon Medical School Musashi Kosugi Hospital · 2026-02-27
  2. [2][Official]当院へのサイバー攻撃による個人情報漏洩に関するご報告とお詫び（第7報）Nippon Medical School Musashi Kosugi Hospital · 2026-04-09