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Gas Main Location Check Service

Gas Main Location Check Service (run by Tokyo Gas Co., Ltd.) was hit in 1 recorded cybersecurity incident. The latest was disclosed on 2026-10-29.

About the service

Website

https://itm-external22.tokyo-gas.co.jp/maicho

Run by

Tokyo Gas Co., Ltd.

Category

Other

For

Businesses

Incident history

Disclosed 2026-10-29Updated 2026-11-13Aichi, Akita, Aomori, Chiba, Fukui, Fukuoka, Fukushima, Gifu, Gunma, Hiroshima, Hokkaido, Hyogo, Ibaraki, Iwate, Kagawa, Kagoshima, Kanagawa, Kochi, Kyoto, Mie, Miyagi, Miyazaki, Nagano, Nagasaki, Niigata, Okayama, Okinawa, Osaka, Saga, Saitama, Shiga, Shizuoka, Tochigi, Tokushima, Tokyo, Toyama, Wakayama, Yamagata, Yamaguchi, Yamanashi[Investigating][Severity: Critical][Through a supplier][Major]
Arara: 81,329,467 email addresses leaked or at risk, affecting up to about 380 clients
[Web app exploit][Data leak][Service outage]Leaked 81.3MOrganizations 380

		Incident	Role	Impact level				Methods	Impacts		Status
2026-10-29	2026-11-13	Arara: 81,329,467 email addresses leaked or at risk, affecting up to about 380 clients	[Through a supplier]	[Major]	[Critical]	380 Osaka City, Sumitomo Mitsui Banking Corporation, Internet Initiative Japan Inc., Mitsui Fudosan Co., Ltd., Mos Food Services, Inc., Yamanashi Prefecture, AIRDO Co., Ltd., Arara Inc., Asoview Inc., Avance System Co., Ltd., Axel Entermedia Inc., Belc Co., Ltd., Bijyu Co., Ltd., Camel Coffee Co., Ltd., Chobirich Inc., DATA X, Inc., Duskin Co., Ltd., Fujiya Co., Ltd., GMO MAKESHOP Co., Ltd., GMO Payment Service Inc., Hokuriku Electric Power Company, HR Solutions, Inventit, Japan Leisure Channel Co., Ltd., Java Corporation, Jupiter Golf Network Co., Ltd., Kakaku.com, Inc., Kintetsu Miyako Hotels Inc., Life Corporation, Maker's Shirt Kamakura, Martial Arts Legal Professional Corporation, Matsui Securities Co., Ltd., Monteroza Co., Ltd., NTT TownPage, ODK Solutions, Sakai City, Sasebo City, Shochiku Multiplex Theatres Inc., Solaseed Air Inc., St. Cousair Co., Ltd., Sumitomo Realty & Development Co., Ltd., Takii, TKC Corporation, U Co-op, Workman Co., Ltd., Zaif Inc., Cabinet Office, Ministry of Internal Affairs and Communications, Tokyo Metropolitan Police Department, Aioi Nissay Dowa Insurance Co., Ltd., City of Sendai, City of Yokohama, Fujitsu Limited, Fukuoka City, Honda Motor Co., Ltd., JTB Corp., Kawasaki City, Kyoto City, Kyushu Railway Company, Mitsui Sumitomo Insurance Company, Limited, Miyazaki Prefecture, Okayama Prefecture, Okinawa Prefectural Government, Osaka Prefectural Government, Osaka Prefectural Police, Saitama Prefecture, Shiga Prefecture, Suzuki Motor Corporation, Yamada Denki Co., Ltd., Yamaguchi Prefecture, Akita Prefecture, Daito City, Edogawa City, Fuji Television Network, Inc., Fukui Prefecture, Fukushima City, Himeji City, Human Academy Co., Ltd., Isahaya City, Isesaki City, Iwata City, The Kagoshima Bank, Ltd., Karatsu City, Kariya City, Kawaguchi City, Kinko's Japan Co., Ltd., Koriyama City, Kumagaya City, Marugame City, Matsudo City, Miyazaki City, Naha City, Nasushiobara City, Nishinomiya City, Odawara City, Okazaki City, Otsu City, Saga Prefecture, SEGA FAVE Corporation, Shimonoseki City, Suzuka City, Takatsuki City, Toda City, Tokyo Gas Co., Ltd., Toyama Prefectural Government, Toyohashi City, Utsunomiya City, Yao City, ADS LLC, Aikawa Town, AKASE GROUP Co., Ltd., Akita City, Akita Furusato Mura Co., Ltd., Albait Times Co., Ltd., Aohata Corporation, Asahi Gakken Thinquest Co., Ltd., Asahi Mutual Life Insurance Company, ASOBISYSTEM Co., Ltd., Avanti Staff Co., Ltd., AWS Co., Ltd., Aya Town, Bank of the Ryukyus, Limited, Barnes de Stroes Japan Limited, Bean Stalk Snow Co., Ltd., BEENOS Entertainment Inc., Bic Camera Inc., BOATRACE Promotion Association, Bunri Co., Ltd., The Chiba Kogyo Bank, Ltd., Chiba Lotte Marines Co., Ltd., Chiiki Shosha Yamaguchi Co., Ltd., Co-op Aichi, Co-op Gifu, Co-op Mie, Congrès Inc., Cosmo Energy Holdings Co., Ltd., CYBIRD Co., Ltd., Densan Co., Ltd., Deria Foods Co., Ltd., DH Inc., e-CHANNEL Co., Ltd., Echizen Mikuni Boat Race Authority, Ekitan & Co., Ltd., Euglena Co., Ltd., EVENTIFY Inc., Fanplus, Finnovalley Inc., Fire Equipment and Safety Center of Japan, Fleekdrive Inc., Fujiidera City, Fujinomiya City, Fukui Shimbun Co., Ltd., Fukuoka Chikagai Kaihatsu Co., Ltd., Fukuoka SoftBank Hawks Corp., Furukawa Electric Health Insurance Society, Fussa City, Gakken Cocofump Co., Ltd., Gakken Educational Co., Ltd., Gakken Holdings, Gakken Inc., Gakken LEAP Co., Ltd., Gakken Logistics Co., Ltd., Gakken Medical Support Co., Ltd., Gakken Products Support Co., Ltd., Gakken SEED Co., Ltd., Gakken Smileheartful Co., Ltd., Giftpad Inc., GMO Epsilon, Gold Flag Co., Ltd., Granvista Hotels & Resorts, Grateful Mind Corporation, Hakone Town, Hamanako Boat Race Authority, Hanamaki City, Hasegawa Co., Ltd., Higashikurume City, Higashimurayama Regional Promotion Organization, Hinode Publishing Co., Ltd., Hirano Masakichi Art Foundation, Hokkaido Nippon-Ham Fighters Co., Ltd., Honjo City, Human Resocia, ILL, ING Co., Ltd., Itako City, Itami City, its communications Inc., Iwaki City, Iwamizawa City, Iwate Prefectural University, Izumisano City, Japan Digital Laboratory, Japan Football Association, Japan Society of Civil Engineers, JERA Co., Inc., Joseikan Co., Ltd., The Juhachi-Shinwa Bank, Ltd., Kagoshima Shinkin Bank, Kagoshima Sogo Shinkin Bank, Kainan City, Kaisei Town, Kameyama City, Kanagawa Municipal Employees Mutual Aid Association, Kanagawa Municipal Information System Association, Kanegasaki Town, Kasama City, Kashiwazaki City, Keimix Public Business Co., Ltd., Kewpie Corporation, Kintetsu Real Estate Co., Ltd., Kirihara Shoten K.K., Kitamoto City, Kiyosu City, Kobe City, Kobe Shimbun Inc., Kotsu Shimbunsha, Kracie Pharmaceutical, Ltd., Kurihara City, Lee Mills & Company Co., Ltd., LightUp Shopping Club Inc., M.STAGE Co., Ltd., M.STAGE Management Solutions Co., Ltd., Manazuru Town, Manbou Corp., Matsuda Town, MBK Allied Health Insurance Society, Medical Care Service Co., Ltd., Medicus Shuppan, Publishers Co., Ltd., MERY Co., Ltd., Mibu Town, The Minami-Nippon Bank, Ltd., Minkabu The Infonoid, Miroku Jyoho Service Co., Ltd., Misato Town (Saitama), Mitsubishi UFJ Financial Group, Inc., Mitsui Direct General Insurance Co., Ltd., Miyoshi Town, Moka City, Motegi Town, Musashimurayama City, Mutsu City, Nagakute City, Naka City, Nakai Town, Naruto City, Natural Island Co., Ltd., Natural Science Co., Ltd., NEO CAREER Co., Ltd., Nihon Fukushi University, Ninomiya Town, Nishio City, Nishitetsu Hotels Co., Ltd., Nishitokyo City, Nishiwaki City, Nittobo Health Insurance Society, Nomura Holdings, Inc., Nyuzen Town, Obanazawa City, Odakyu Travel Inc., Officemotion Co., Ltd., Oga Aquarium Co., Ltd., Ohtawara City, Oi Town, Oiso Town, Okayama Prefectural Industrial Promotion Foundation, Okinawa Churashima Foundation, Ome City, Osaka Gas Co., Ltd., Pacific League Marketing Corporation, Paris Miki Asset Management Co., Ltd., Rakuten Baseball, Inc., Rakuten Securities, Inc., Ryobi Holdings Co., Ltd., Saitama Parks and Greenery Association, Saito City, Sakai Chamber of Commerce and Industry, Salad Club, Inc., Samantha Thavasa Japan Limited, Sanjo City, Sano City, SEGA Corporation, Seibu Lions Co., Ltd., Seijo Ishii Co., Ltd., Setagaya Shopping District Promotion Association Federation, Shimotsuke city, Shioya Town, Shogakukan Inc., Sodegaura City, Sofmap Co., Ltd., Sony Financial Group Inc., Sozo Gakuen Co., Ltd., T-PEC Corporation, Tajimi City, Taka Town, Takanezawa town, Takeda Printing Co., Ltd., Tama Shinkin Bank, Terravie Inc., Ticketplus, Inc., The Tochigi Bank, Ltd., Toho Cash and Carry, Tokyo Convention & Visitors Bureau, TOKYO GLOBAL GATEWAY Co., Ltd., Tokyo Kantei, Tokyo Marathon Foundation, Tomakomai City, Tou Kewpie Co., Ltd., Toyama Prefectural University, Toyoake City, Tribeck Inc., Tsu City, Tsunagu Group Holdings, TV Shinhiroshima Co., Ltd., Ueda City, Ushiku City, VALTES Holdings Co., Ltd., Vendome Yamada Co., Ltd., VOLZ, Inc., WATAMI FAST CASUAL MANAGEMENT Co., Ltd., Watts Co., Ltd., West Japan Packaging Health Insurance Society, WingArc NEX Inc., Yaita City, The Yokohama Rubber Co., Ltd., Yokoshibahikari Town, Yugawara Town, Nagareyama City, Niigata City, AUTHENTIC JAPAN Co., Ltd., ELECOM Co., Ltd., Japan Post Co., Ltd., Kojima Co., Ltd., The Nikkan Kogyo Shimbun, Ltd., Shiki City, Umanity Inc., Warehouse TERRADA, Will Co., Ltd., Itabashi Shopping Street Promotion Association Federation, Maniwa City	Aichi, Akita, Aomori, Chiba, Fukui, Fukuoka, Fukushima, Gifu, Gunma, Hiroshima, Hokkaido, Hyogo, Ibaraki, Iwate, Kagawa, Kagoshima, Kanagawa, Kochi, Kyoto, Mie, Miyagi, Miyazaki, Nagano, Nagasaki, Niigata, Okayama, Okinawa, Osaka, Saga, Saitama, Shiga, Shizuoka, Tochigi, Tokushima, Tokyo, Toyama, Wakayama, Yamagata, Yamaguchi, Yamanashi	[Web app exploit]	[Data leak][Service outage]	81,329,467	[Investigating]

Other incidents of the operator (2)

Disclosed 2024-07-17Updated 2025-01-21Chiba, Kanagawa, Okayama, Tokyo[Contained][Severity: Critical]
Tokyo Gas Engineering Solutions: intrusion
[Intrusion][Data leak]Leaked 4.2MOrganizations 5
Disclosed 2021-01-30Updated 2021-04-26Tokyo[Resolved][Severity: Major]
Tokyo Gas: intrusion into its Furo-koi dating game website
[Intrusion][Data leak][Site defacement]Leaked 10.4KOrganizations 1

		Incident				Methods	Impacts		Status
2024-07-17	2025-01-21	Tokyo Gas Engineering Solutions: intrusion	[Critical]	5 Keiyo Gas Co., Ltd., Okayama Gas Co., Ltd., Tokyo Gas Engineering Solutions Corporation, Kanagawa Prefecture, Tokyo Gas Co., Ltd.	Chiba, Kanagawa, Okayama, Tokyo	[Intrusion]	[Data leak]	4,160,000	[Contained]
2021-01-30	2021-04-26	Tokyo Gas: intrusion into its Furo-koi dating game website	[Major]	1 Tokyo Gas Co., Ltd.	Tokyo	[Intrusion]	[Data leak][Site defacement]	10,365	[Resolved]