SHINDO3

Kyuden T&D

Kyushu Electric Power Transmission and Distribution Co., Inc.

Personal data35,019records

EXPOSEDFull name / Phone numberSoftware defect · Contained

Open in the live monitor ▶
Disclosed
Apr 30, 2025
Leak
Exposed, access unknown
Type
Software defect
Status
Contained
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityCustomer name
ContactContact details
Transactions & activityType of grid connection service

How many

  • Customer records viewable by retailers with no contract with the customer 35,019 records
  • Records with customer name, contact details and grid service type 258 records
  • Records with customer name only 34,761 records

Who is affected

  • Customers

Cause

A program design error in the system that supports switching of grid-use (wheeling) contracts

Timeline

  1. Contained
  2. Date of the Security NEXT report

Response

  • Change process

Finished fixing the system on April 15

What you should do

  1. Treat refund or apology calls and texts as scams. Call back only on the number from the official site
  2. Check the company's notice to see if you're affected

Lessons for companies

  1. Never sit on a known defect. Test every change before production
  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