> JapanHacked_Cybersecurity incidents in Japan

Company

Mitsui Sumitomo Aioi Life Insurance Co., Ltd.

Mitsui Sumitomo Aioi Life Insurance Co., Ltd. (Chuo, Tokyo; Finance and insurance) appears in 1 related cybersecurity incident. The latest was disclosed on 2026-11-03.

Profile

Industry/type: Finance and insurance
Location: Tokyo, Chuo
Website: https://www.msa-life.co.jp/

Public figures

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Metric	Value	Scope	As of	Source
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Incident history

Disclosed 2026-11-03Updated 2026-11-06 16:02Tokyo[Investigating][Severity: Major][Through a supplier][Major]
Mitsui Sumitomo and Aioi Nissay Dowa: unauthorized access to policyholder sites leaks about 480,000 customer records
[Intrusion][Service outage][Data leak]Leaked 444KOrganizations 3

		Incident	Role	Impact level				Methods	Impacts		Status
2026-11-03	2026-11-06 16:02	Mitsui Sumitomo and Aioi Nissay Dowa: unauthorized access to policyholder sites leaks about 480,000 customer records	[Through a supplier]	[Major]	[Major]	3 Aioi Nissay Dowa Insurance Co., Ltd., Mitsui Sumitomo Insurance Company, Limited, Mitsui Sumitomo Aioi Life Insurance Co., Ltd.	Tokyo	[Intrusion]	[Service outage][Data leak]	444,000	[Investigating]