Banking and investing
Mitsui Sumitomo Insurance business web service
Mitsui Sumitomo Insurance business web service (run by Mitsui Sumitomo Insurance Company, Limited) was hit in 1 recorded cybersecurity incident. The latest was disclosed on 2026-11-03.
About the service
- Website
- https://www.ms-ins.com/business/web_service/
- Run by
- Category
- Banking and investing
- For
- Businesses
Incident history
Disclosed 2026-11-03Updated 2026-11-04 12:44Tokyo[Investigating][Severity: Moderate][Breached][Moderate]
Mitsui Sumitomo and Aioi Nissay Dowa: unauthorized access detected, policyholder sites taken offline[Intrusion][Service outage]Organizations 2
Other incidents of the operator (4)
Disclosed 2026-04-24Updated 2026-04-27 08:05Aichi, Tokyo[Investigating][Severity: Moderate]
Mitsui Sumitomo Insurance: secondees leak Toyota data[Insider][Data leak]Organizations 2Disclosed 2025-11-27Updated 2026-05-11Tokyo[Contained][Severity: Major]
Shin Nihon Kentei Kyokai: ransomware attack[Ransomware][Data leak][Service outage]Leaked 30KOrganizations 5Disclosed 2024-10-07Updated 2025-02-17Tokyo[Contained][Severity: Critical]
Tokyo Sonpo Kantei: ransomware puts insurers' customer data at risk[Ransomware][Credential abuse][Data leak][Extortion]Leaked 120KOrganizations 6Disclosed 2021-05-31Updated 2021-06-02 08:00Tokyo[Investigating][Severity: Major]
Nippon Kaiji Kentei Kyokai: Singapore office cyberattack[Unknown][Data leak]Organizations 2