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Government

Bureau of Waterworks Tokyo Metropolitan Government

Bureau of Waterworks Tokyo Metropolitan Government (Shinjuku, Tokyo; Electricity, gas, heat and water) appears in 2 related cybersecurity incidents. The latest was disclosed on 2026-10-23.

Profile

Industry/type: Electricity, gas, heat and water
Location: Tokyo, Shinjuku
Also known as: Tokyo Waterworks Bureau
Website: https://www.waterworks.metro.tokyo.lg.jp/
Operated by: Tokyo Metropolitan Government

Public figures

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Incident history

Disclosed 2026-10-23Updated 2026-10-24 03:51Tokyo[Investigating][Severity: Moderate][Breached][Moderate]
Tokyo Waterworks Bureau: four external hard drives holding personal data lost
[Lost device][Data leak]Leaked 1.9KOrganizations 1
Disclosed 2026-03-06Updated 2026-10-24 03:51Kanagawa, Tokyo[Resolved][Severity: Moderate][Through a supplier][Moderate]
Seed Planning: ransomware attack
[Ransomware][Service outage]Leaked 130KOrganizations 4

		Incident	Role	Impact level				Methods	Impacts		Status
2026-10-23	2026-10-24 03:51	Tokyo Waterworks Bureau: four external hard drives holding personal data lost	[Breached]	[Moderate]	[Moderate]	1 Bureau of Waterworks Tokyo Metropolitan Government	Tokyo	[Lost device]	[Data leak]	1,932	[Investigating]
2026-03-06	2026-10-24 03:51	Seed Planning: ransomware attack	[Through a supplier]	[Moderate]	[Moderate]	4 Bureau of Waterworks Tokyo Metropolitan Government, Tokyo Metropolitan Government, Kawasaki City, Seed Planning, Inc.	Kanagawa, Tokyo	[Ransomware]	[Service outage]	130,000	[Resolved]