Overview
4,611 people: names, email addresses and other fields. The company says this data alone does not enable account takeover or unauthorised trades.
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
- 外部委託先への不正アクセスに伴うお客様情報の漏洩について岩井コスモ証券株式会社 · 2026-11-09