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574 results
Disclosed 2024-11-15Updated 2026-10-23Tokyo[Investigating][Severity: Moderate]
Japan Electric Association: ransomware hits the newspaper division's business system with customer data[Ransomware][Service outage]Organizations 1Disclosed 2024-11-08Updated 2026-10-23Tokyo[Resolved][Severity: Major]
AIS: ransomware; business partners' personal data may have leaked[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2024-11-08Updated 2026-10-23Tokyo[Contained][Severity: Moderate]
Toyota Mobility Tokyo: employee temporarily lost a personal USB stick holding data of 9,489 staff and others[Lost device][Data leak]Leaked 9.5KOrganizations 1Disclosed 2024-11-08Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
Welcia Yakkyoku: support scam gave remote access to an employee's PC; data of about 40,000 Welcia.com customers at risk[Phishing][Data leak]Leaked 39.8KOrganizations 1Disclosed 2024-11-06Updated 2026-10-23Miyagi[Resolved][Severity: Major]
Tohoku Gakuin: ransomware on a work PC leaks 7,085 records including student grades[Ransomware][Credential abuse][Data leak]Leaked 7.1KOrganizations 1Disclosed 2024-10-25Updated 2026-10-23Oita[Investigating][Severity: Major]
Betsudaikohsan: ransomware, with a threat to sell the data[Ransomware][Misconfiguration][Service outage][Data leak][Extortion]Organizations 4Disclosed 2024-10-24Updated 2026-10-23Osaka[Resolved][Severity: Moderate]
Sanko Air Plant: ransomware; attackers abused a guest account over VPN[Ransomware][Credential abuse][Service outage][Extortion]Organizations 1Disclosed 2024-10-24Updated 2026-10-23Yamanashi[Contained][Severity: Critical]
Slow Village: personal data of 32,345 customers, including card data of 4,494, may have leaked from its online shop[Web app exploit][Data leak][Fraud]Leaked 32.3KOrganizations 1Disclosed 2024-10-22Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Burger King: unauthorized access to the official app leaked email addresses and passwords of 38 members[Intrusion][Data leak]Leaked 38Organizations 1Disclosed 2024-10-22Updated 2026-10-23Tokyo[Contained][Severity: Major]
KidZania: unauthorized access to the website leaked personal data of 24,644 KidZania Tokyo bookers[Web app exploit][Data leak]Leaked 24.6KOrganizations 1Disclosed 2024-10-21Updated 2026-10-23Tokyo[Contained][Severity: Critical]
MTI: ransomware through stolen credentials; staff and partner data may have leaked[Ransomware][Credential abuse][Data leak]Organizations 1Disclosed 2024-10-18Updated 2026-10-23Saitama[Investigating][Severity: Major]
Nexus-Shinozaki Transport & Logistics: file server accessed; partner contact names and quote and invoice data may have leaked[Intrusion][Data leak]Organizations 1Disclosed 2024-10-18Updated 2026-10-23Kanagawa[Investigating][Severity: Critical]
Yorozu: ransomware halts core systems and delays its earnings report[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2024-10-16Updated 2026-10-23Saitama[Contained][Severity: Major]
Saizeriya: ransomware exposes about 60,000 records of staff and business partners[Ransomware][Data leak][Service outage]Leaked 58.9KOrganizations 1Disclosed 2024-10-10Updated 2026-10-23Kanagawa[Investigating][Severity: Major]
Kanagawa Sewerage Public Corporation: BlackSuit ransomware on servers and PCs; personal data may have leaked[Ransomware][Data leak]Organizations 1Disclosed 2024-10-08Updated 2026-10-23Tokyo[Contained][Severity: Major]
Casio: ransomware leaks employee, partner and customer personal data[Ransomware][Service outage][Data leak][Extortion]Leaked 6.5KOrganizations 1Disclosed 2024-10-08Updated 2026-10-23Aichi[Contained][Severity: Major]
CoCo Ichibanya: unauthorized access to the catering inquiry form; 172 applicants' data became viewable outside[Intrusion][Data leak]Leaked 172Organizations 1Disclosed 2024-10-07Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Tokyo Sonpo Kantei: ransomware puts customer data of several insurers at risk[Ransomware][Credential abuse][Data leak][Extortion]Leaked 120KOrganizations 6Disclosed 2024-10-02Updated 2026-10-23Kyoto, Nara[Contained][Severity: Moderate]
Kyocera Communication Systems: ransomware hits Ikaruga town library's new system just before launch through flawed access settings[Ransomware][Misconfiguration][Credential abuse][Service outage]Leaked 22KOrganizations 2Disclosed 2024-10-01Updated 2026-10-23Chiba, Kanagawa, Tokyo[Contained][Severity: Critical]
Like Kids: ransomware; about 158,000 personal data records may have been viewed[Ransomware][Intrusion][Data leak][Service outage]Leaked 158.4KOrganizations 6Disclosed 2024-09-27Updated 2026-10-23Tokyo[Contained][Severity: Major]
J PREP: Saito Juku staff email account accessed[Credential abuse][Data leak]Organizations 1Disclosed 2024-09-27Updated 2026-10-23Aichi[Investigating][Severity: Major]
Nagoya University: researcher exchange site 100-nin RONBUN defaced; participant data may have leaked[Unknown][Site defacement][Data leak]Organizations 1Disclosed 2024-09-26Updated 2026-10-23Tokyo[Resolved][Severity: Major]
Bell Data: ransomware; about 47,000 business card and employee records may have been viewed[Ransomware][Data leak][Service outage]Leaked 47.4KOrganizations 1Disclosed 2024-09-26Updated 2026-10-23Osaka[Contained][Severity: Major]
Otsuka Toshimi Scholarship Foundation: unauthorized access to the scholars' page[Web app exploit][Data leak]Organizations 1Disclosed 2024-09-26Updated 2026-10-23Nagano[Contained][Severity: Critical]
Shinshu University: personal data leaked from the teacher-training course system[Intrusion][Data leak]Leaked 4.1KOrganizations 1Disclosed 2024-09-20Updated 2026-10-23Osaka[Investigating][Severity: Moderate]
Hanwa: apparent ransomware attack on its Thai subsidiary; group file server also accessed[Ransomware]Organizations 1Disclosed 2024-09-20Updated 2026-10-23Hyogo[Resolved][Severity: Moderate]
Ishimitsu: ransomware, starting with remote desktop access to a group company's SIM-equipped laptop[Ransomware][Data leak][Service outage]Organizations 1Disclosed 2024-09-19Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Kenbiya: database backup accessed; member and inquiry-user data may have been viewed[Intrusion][Data leak]Leaked 218KOrganizations 1Disclosed 2024-09-19Updated 2026-10-23Saitama, Tokyo[Contained][Severity: Critical]
Sougyo Service: ransomware; customer data of clients such as Shochiku and Taiju Life may have leaked[Ransomware][Intrusion][Data leak][Service outage]Leaked 218.2KOrganizations 4Disclosed 2024-09-17Updated 2026-10-23Tokyo[Contained][Severity: Critical]
PERSOL Career: a flaw in the doda system for ad sales agencies let agencies view data of 549,195 recruiters[Misconfiguration][Data leak]Leaked 549.2KOrganizations 1Disclosed 2024-09-15Updated 2026-10-23Tokyo[Contained][Severity: Critical]
ZACROS: ransomware; 38 staff records confirmed leaked and wider personal data at risk[Ransomware][Service outage][Data leak][Extortion]Leaked 143.7KOrganizations 1Disclosed 2024-09-13Updated 2026-10-23Hyogo, Osaka[Contained][Severity: Critical]
Kantsu: ransomware stops Cloud Thomas and other warehouse systems, halting client shipments[Ransomware][Service outage][Data leak]Leaked 4.7KOrganizations 4Disclosed 2024-09-06Updated 2026-10-23Shizuoka[Contained][Severity: Moderate]
Miyaki: ransomware halts production lines for two days[Ransomware][Service outage]Organizations 1Disclosed 2024-09-05Updated 2026-10-23Chiba[Investigating][Severity: Critical]
Fukui Denki: ransomware hits a file server; partner and employee data may have leaked[Ransomware][Data leak][Service outage]Organizations 1Disclosed 2024-09-02Updated 2026-10-23Osaka[Investigating][Severity: Moderate]
Marukan: ransomware encrypts some servers[Ransomware][Service outage]Organizations 1Disclosed 2024-08-30Updated 2026-10-23Chiba[Contained][Severity: Critical]
Hiroike Gakuen: ransomware after an intrusion in March; student and parent data at risk[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2024-08-30Updated 2026-10-23Chiba[Investigating][Severity: Major]
Moralogy Foundation: ransomware; supporter and partner data may have been viewed or taken[Ransomware][Data leak][Service outage]Organizations 1Disclosed 2024-08-28Updated 2026-10-23Hyogo[Contained][Severity: Critical]
Edelweiss: card data at risk at its Wittamer and Antenor online shops (45,355 and 7,018 records)[Web app exploit][Data leak][Fraud]Leaked 45.4KOrganizations 1Disclosed 2024-08-28Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Sanofi: unauthorized access to a database; data of 730,000 healthcare professionals may have leaked[Malware][Credential abuse][Data leak]Leaked 733.8KOrganizations 1Disclosed 2024-08-26Updated 2026-10-23Tokyo[Contained][Severity: Major]
Avenue: ransomware through a maintenance contractor's settings error; tenant data at risk[Ransomware][Misconfiguration][Data leak]Organizations 1Disclosed 2024-08-26Updated 2026-10-23Osaka[Resolved][Severity: Moderate]
KISCO: ransomware, starting from a firewall used for overseas remote access[Ransomware][Credential abuse][Service outage][Extortion]Organizations 1Disclosed 2024-08-23Updated 2026-10-23Tokyo[Contained][Severity: Major]
J-Will Partners: unauthorized access to an employee's email account; personal data of 7,132 people may have leaked[Credential abuse][Data leak]Leaked 7.1KOrganizations 1Disclosed 2024-08-23Updated 2026-10-23Osaka[Investigating][Severity: Moderate]
Kowa: ransomware encrypts business data and software[Ransomware][Service outage]Organizations 1Disclosed 2024-08-16Updated 2026-10-23Tokyo[Resolved][Severity: Moderate]
Nichii: ransomware on group PCs encrypts about 26,000 files; no trace of a leak[Ransomware]Organizations 2Disclosed 2024-08-09Updated 2026-10-23Hyogo[Contained][Severity: Major]
e431: ransomware hits an internal server; pre-2021 online shop customer data may have leaked[Ransomware][Data leak]Organizations 1Disclosed 2024-08-05Updated 2026-10-23Saitama[Contained][Severity: Critical]
Mitsubishi Electric Home Appliance: intrusion also reached a server holding data of about 2.31 million customers[Intrusion][Data leak]Leaked 2.3MOrganizations 1Disclosed 2024-07-31Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Tokyo Tamago Honpo: card data (65,387 records) and personal data (73,961 records) may have leaked from its Tokyo Tamago Gomatamago online shop[Web app exploit][Data leak]Leaked 74KOrganizations 1Disclosed 2024-07-19Updated 2026-10-23Hokkaido[Contained][Severity: Major]
Matec: Akira ransomware, likely through a UTM flaw and a misused VPN account[Ransomware][Credential abuse][Data leak][Service outage][Extortion]Organizations 1Disclosed 2024-07-18Updated 2026-10-23Tokyo[Investigating][Severity: Moderate]
Murayama: ransomware encrypts a business data server[Ransomware]Organizations 1Disclosed 2024-07-18Updated 2026-10-23Kyoto[Contained][Severity: Critical]
Shimogamo Saryo: card data of 16,682 and personal data of 19,235 customers may have leaked from its online shop[Web app exploit][Data leak][Fraud]Leaked 19.2KOrganizations 1