SHINDO4

Anabuki Housing Service Co., Ltd.

Personal data207,773records

LEAK CONFIRMEDPostal address / Phone numberRansomware · Closed (final report)

Open in the live monitor ▶
Disclosed
Feb 3, 2026
Detected
Feb 3, 2026 05:28 JST
Detection to disclosure
Same day
Leak
Leak confirmed
Type
Ransomware
Status
Closed (final report)
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityFull name
ContactAddress, Phone number, Email address

Not leaked

  • Credit card information
  • Bank account information
  • My Number

How many

  • Confirmed number of leaked personal records 207,773 records
  • Of which Matsuyama municipal housing tenant records (announced by Matsuyama City) 7,237 records

Who is affected

  • People whose personal data was held (breakdown not given in the article)
  • Tenants of Matsuyama municipal housing

Cause

Attackers exploited a vulnerability in a group company's network device and deployed ransomware

Timeline

  1. First report
  2. Intrusion and ransomware encryption found
  3. Second report
  4. Third report
  5. Posting on the leak site confirmed
  6. Fourth report
  7. Fifth report
  8. Sixth report (leak count finalized)
  9. Reported to the Personal Information Protection Commission
  10. Reported to MLIT Shikoku and Kanto Regional Development Bureaus and the Okinawa General Bureau

Response

  • Governance / committee
  • Patched

Adopted a zero-trust architecture, fully retired the legacy IT environment and replaced all company PCs

What you should do

  1. Don't open links in emails from this company. The apology email itself may be fake
  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. Patch internet-facing servers, VPNs and admin panels first. Exploits follow disclosure within days
  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