SHINDO3

Saitama Prefecture

Personal dataup to80,000records

POSSIBLE LEAKHealth / medical / treatment / Date of birthLoss · Investigating

Open in the live monitor ▶
Disclosed
Jan 7, 2026
Leak
Leak possible
Type
Loss
Status
Investigating
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityName, Date of birth, Gender, Age
Special-care dataWhether medical institutions were visited, specific health checkup status

How many

  • Residents of five municipalities up to 80,000 records
  • Names and birthdates of residents of seven municipalities up to 70 records

Who is affected

  • Residents of municipalities in the prefecture

Cause

A contractor's employee left a work laptop on a train and lost it

Timeline

  1. Contractor employee left the PC on a train
  2. Security NEXT report date

Response

  • Revoked credentials
  • Vendor review

Disabled the cloud storage account after discovery; instructed the contractor to keep searching and to prevent recurrence through proper data handling

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