> JapanHacked_Cybersecurity incidents in Japan

Company

Aioi Nissay Dowa Insurance Co., Ltd.

Aioi Nissay Dowa Insurance Co., Ltd. (Shibuya, Tokyo; Finance and insurance) appears in 1 related cybersecurity incident. The latest was disclosed on 2025-11-27.

Profile

Industry/type: Finance and insurance
Location: Tokyo, Shibuya
Website: https://www.aioinissaydowa.co.jp/

Public figures

Employees12,515Non-consolidated2026-03-31
METI: Gビズインフォ
Capital¥100BNon-consolidated2026-03-31
METI: Gビズインフォ

Metric	Value		As of	Source
Employees	12,515	Non-consolidated	2026-03-31	METI: Gビズインフォ
Capital	¥100B	Non-consolidated	2026-03-31	METI: Gビズインフォ

Incident history

Disclosed 2025-11-27Updated 2026-10-23Tokyo[Contained][Severity: Major][Through a supplier][Major]
Shin Nihon Kentei Kyokai: ransomware attack
[Ransomware][Data leak][Service outage]Leaked 30KOrganizations 5

		Incident	Role	Impact level				Methods	Impacts		Status
2025-11-27	2026-10-23	Shin Nihon Kentei Kyokai: ransomware attack	[Through a supplier]	[Major]	[Major]	5 Aioi Nissay Dowa Insurance Co., Ltd., Mitsui Sumitomo Insurance Company, Limited, Sompo Japan Insurance Inc., Tokio Marine & Nichido Fire Insurance Co., Ltd., Shin Nihon Kentei Kyokai	Tokyo	[Ransomware]	[Data leak][Service outage]	30,000	[Contained]