Overview
“Up to 843” → blank.
Timeline
- Occurred
- Discovered
- 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
- 【重要】コミュニティサイト「ちとせアカデミー」への不正アクセスによる個人情報流出可能性に関するお知らせとお詫び株式会社ちとせ研究所 · 2026-11-09