SHINDO4

Nabari Kintetsu Gas

Nabari Kintetsu Gas Co., Ltd.

Propane gas customers~6,800records

POSSIBLE LEAKPostal address / Phone numberRansomware · Investigating

Open in the live monitor ▶
Disclosed
Sep 30, 2026
Leak
Leak possible
Type
Ransomware
Status
Investigating
Security spend
Measures, no amount
Compensation
Not announced
Corporate number
9190001009427

What leaked

IdentityFull name
ContactAddress, Phone numbers for 2 records
Account dataBilling number

Not leaked

  • Bank account numbers and credit card information are not included
  • Bank account numbers and credit card information are not included

How many

  • Propane gas customers ~6,800 records

Who is affected

  • Propane gas customers

Cause

The file server of Ryomo Systems, to which the company outsources customer information management, suffered unauthorized access by ransomware

Timeline

  1. First disclosure

Response

  • Notified individuals
  • Phishing warning
  • Hotline

Affected customers are being contacted individually. Warning about suspicious calls, emails and SMS pretending to be the company. Contacts: Nabari Kintetsu Gas customer desk (0120-488-033) and Ryomo Systems (0120-998-970)

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. Watch for unexpected mail or invoices; your address is hard to change
  3. 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. Offline backups with restore drills; segment the network
  3. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  4. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources