SHINDO4

Himawari Shinkin

Himawari Shinkin Bank

Customer records936records

LEAK UNCLEARBank account / Postal addressImproper disposal · Closed (final report)

Open in the live monitor ▶
Disclosed
Aug 28, 2025
Detected
Jul 3, 2025
Detection to disclosure
56 days
Leak
Unknown
Type
Improper disposal
Status
Closed (final report)
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityName or company name, Date of birth, Seal impression (image)
ContactAddress, Phone number
Employment & HREmployer
Financial & paymentContract amount, Account number

How many

  • Customer records 936 records
  • Fixed deposit application and seal forms (12 bound volumes) ~1,667 files

Who is affected

  • Customers

Cause

Most likely discarded by mistake during document disposal work

Timeline

  1. Date of disposal work
  2. Found in an internal audit
  3. Date of the Security NEXT report

Response

  • Governance / committee

What you should do

  1. Scammers who know your account number pose as refund staff. No bank or company asks for your PIN
  2. Treat refund or apology calls and texts as scams. Call back only on the number from the official site
  3. Watch for unexpected mail or invoices; your address is hard to change
  4. Check the company's notice to see if you're affected

Lessons for companies

  1. Don't keep ID or bank data: delete after checks or use a KYC provider
  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