Investigating

Hachioji Gakuen: ransomware attack may have exposed current/former students’ and related personal data

Possible data leak: First notice Jul 13, 2026 reported ransomware on some servers. Second notice (Sep 30) details Jul 8 intrusion / Jul 10 encryption of files including current/former students, applicants, guardians, staff and retirees. No clear exfiltration traces, but log deletion prevents fully ruling out leakage. No count. First disclosure remains Jul 13.

Last updated: 2026-11-09

Overview

No published headcount → blank.

Timeline

  1. Occurred
  2. Discovered
  3. Disclosed

Organization response

Per the notice, the organisation investigated and contained the incident, notified individuals and offered monitoring or protective resources.

What you can do

Be wary of emails, SMS or calls impersonating the organisation; do not open links or attachments or enter passwords or card details. Change reused passwords on other services.

Sources

  1. 本校を標的にしたサイバー攻撃について(第2報)学校法人八王子学園 八王子中学校・高等学校 · 2026-11-09
  2. 本校を標的にしたサイバー攻撃につきまして学校法人八王子学園 八王子中学校・高等学校 · 2026-11-09

Related information

Share a report

No published information yet

Information appears here after source checks or moderation.

Comments and replies

Write a comment

No account needed. Comments appear immediately.

Do not post private names, addresses, passwords, or codes. Automatic masking is limited; review your content before submitting.

Required fields are marked *.

After submitting the text, you can redact and attach images.

Loading the security check. You can submit once it is complete.