Overview
“About 124,000” → 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
- システムサービス提供事業者へのサイバー攻撃に伴うお客さま情報流出の可能性について大東ガス株式会社 · 2026-11-09