SHINDO4

Hosei University

Total16,542people

POSSIBLE LEAKPhone number / Full nameUnauthorized access · Contained

Open in the live monitor ▶
Disclosed
Aug 7, 2025
Detected
Apr 17, 2025
Detection to disclosure
112 days
Leak
Leak possible
Type
Unauthorized access
Status
Contained
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityFull name
ContactPhone number, Email address
Employment & HRAffiliation
Account dataIntegrated authentication ID

How many

  • Total 16,542 people
  • Students (enrolled 2000 to 2022) 8,363 people
  • Faculty and staff (2018 to 2022) 7,438 people
  • Category unknown 741 people

Who is affected

  • Students
  • Faculty and staff

Cause

Network management contractor NS Solutions was hit by an attack exploiting a zero-day vulnerability, and the compromised data included the university's information

Timeline

  1. Contractor confirmed the unauthorized access
  2. University informed by the contractor
  3. Reported to the education ministry and the Personal Information Protection Commission between April and early May
  4. Date of the Security NEXT report

Response

  • Notified individuals

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. Expect targeted phishing posing as HR or interview contacts
  4. 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