SHINDO3

Mutual Aid Association of Prefectural Government Personnel

Personal data726people

POSSIBLE LEAKHealth / medical / treatment / Date of birthMisdelivery · Contained

Open in the live monitor ▶
Disclosed
Sep 4, 2026
Detected
Aug 20, 2026
Detection to disclosure
15 days
Leak
Leak possible
Type
Misdelivery
Status
Contained
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityFull name, Date of birth, Gender
ContactEmail address, Addresses and phone numbers (for some people), Addresses and phone numbers (for some people)
Account dataMember symbol and number
Special-care dataType of specific health guidance support and information on hypertension, diabetes and dyslipidemia

How many

  • Association members and others 726 people

Who is affected

  • Association members and others

Cause

An employee of the contractor RIZAP entered members' personal data into an external generative AI service for personal use during data extraction work

Timeline

  1. Found during data extraction work
  2. First disclosure
  3. Affected people notified by email

Response

  • Data deleted
  • Vendor review
  • Notified individuals

Data deleted from the generative AI service. RIZAP was asked for a thorough investigation and preventive measures. Affected people notified by email

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. Don't open links in emails from this company. The apology email itself may be fake
  3. Treat refund or apology calls and texts as scams. Call back only on the number from the official site
  4. Watch for unexpected mail or invoices; your address is hard to change
  5. Check the company's notice to see if you're affected

Lessons for companies

  1. Put security requirements, audit rights and reporting deadlines in vendor contracts
  2. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  3. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources