Overview
205,208 addresses sent October 8-29; no names or addresses. This stems from the Arara email-platform intrusion (recorded separately); the figure is a subset of the vendor scope and must not be added to it.
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
- 弊社委託先が利用するメール配信サービスへの不正アクセスによるメールアドレス流出についてのお詫び住友不動産株式会社 · 2026-11-09