SHINDO4

Niigata University Medical and Dental Hospital

Niigata University

Patientsup to116people

POSSIBLE LEAKHealth / medical / treatment / Member / user IDLoss · Closed (final report)

Open in the live monitor ▶
Disclosed
Mar 25, 2026
Detected
Nov 18, 2025
Detection to disclosure
127 days
Leak
Leak possible
Type
Loss
Status
Closed (final report)
Security spend
Not checked yet
Compensation
Not announced

What leaked

Account dataPatient ID
Special-care dataMain diagnosis and treatment period, Detailed clinical summaries incl. age and gender (up to 18)

Not leaked

  • Patient names, addresses and phone numbers were not included

How many

  • Patients up to 116 people

Who is affected

  • Endocrinology and metabolism patients

Cause

A USB stick used at a meeting went missing; it was not encrypted

Timeline

  1. USB stick used at an internal meeting
  2. Found missing
  3. Loss report
  4. First disclosure

Response

  • Notified individuals
  • Staff training

Notifying patients individually and strengthening staff data-protection training

What you should do

  1. Health data can't be taken back. Don't answer blackmail; call the police (#9110) or the consumer hotline (188)
  2. Check the company's notice to see if you're affected

Lessons for companies

  1. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  2. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources