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574 results
Disclosed 2024-07-17Updated 2026-10-23Chiba, Kanagawa, Okayama, Tokyo[Contained][Severity: Critical]
Tokyo Gas Engineering Solutions: intrusion may have exposed personal data of about 4.16 million people[Intrusion][Data leak]Leaked 4.2MOrganizations 5Disclosed 2024-07-16Updated 2026-10-23Kagawa[Contained][Severity: Critical]
Higashihara Shoten: unauthorized access to the Olive beef Higashihara shop; personal data of 27,561 customers, including 1,703 cards, may have leaked[Web app exploit][Data leak][Fraud]Leaked 27.6KOrganizations 1Disclosed 2024-07-12Updated 2026-10-23Aichi[Contained][Severity: Moderate]
Aika: ransomware hits its servers; leak judged very unlikely[Ransomware][Service outage]Organizations 1Disclosed 2024-07-12Updated 2026-10-23Aichi, Gifu[Resolved][Severity: Major]
Shibayama Consultant: ransomware; personal data from Aichi and Gifu public works may have leaked[Ransomware][Data leak][Service outage]Leaked 42Organizations 4Disclosed 2024-07-09Updated 2026-10-23Chiba[Contained][Severity: Moderate]
QST: ransomware on QST Hospital's clinical research systems, caused by an unpatched network device and shared passwords[Ransomware][Service outage]Organizations 1Disclosed 2024-07-05Updated 2026-10-23Tokyo[Resolved][Severity: Moderate]
UNITEC Foods: intrusion; about 78 GB of data sent out[Intrusion][Data leak]Organizations 1Disclosed 2024-07-02Updated 2026-10-23Tokyo[Contained][Severity: Critical]
HAGS: unauthorized access to hags-ec.com; card data of 1,432 customers and member data may have leaked[Web app exploit][Data leak]Leaked 1.4KOrganizations 1Disclosed 2024-06-26Updated 2026-10-23Hokkaido[Contained][Severity: Critical]
Hokkaido Sanchi Chokuso Center: card data of 18,443 and personal data of 54,583 customers may have leaked from its online shop[Web app exploit][Data leak][Fraud]Leaked 54.6KOrganizations 1Disclosed 2024-06-25Updated 2026-10-23Tokyo[Contained][Severity: Major]
Brave group: responses to several VTuber audition forms left accessible[Misconfiguration][Data leak]Leaked 7KOrganizations 1Disclosed 2024-06-25Updated 2026-10-23Osaka[Contained][Severity: Major]
Komaihaltec: ransomware after an unauthorized remote desktop logon[Ransomware][Credential abuse][Service outage][Data leak]Organizations 1Disclosed 2024-06-20Updated 2026-10-23Fukushima[Contained][Severity: Major]
Hoshi: ransomware; retail customer data may have leaked[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2024-06-18Updated 2026-10-23Fukui, Tokyo[Contained][Severity: Critical]
Shirasaki: ransomware; Otsuka Corporation's customer data may also have leaked[Ransomware][Service outage][Data leak]Leaked 8.4KOrganizations 2Disclosed 2024-06-17Updated 2026-10-23Chiba[Contained][Severity: Critical]
Alpha-uni: unauthorized access to its official shop; card data of 1,054 customers and personal data of 3,126 members may have leaked[Web app exploit][Data leak][Fraud]Leaked 3.1KOrganizations 1Disclosed 2024-06-10Updated 2026-10-23Kyoto, Nagano[Contained][Severity: Critical]
Nidec Instruments: ransomware; partner, customer and employee personal data at risk[Ransomware][Credential abuse][Service outage][Data leak][Extortion]Leaked 318.2KOrganizations 2Disclosed 2024-06-10Updated 2026-10-23Kanagawa[Resolved][Severity: Moderate]
Oiles: ransomware; attackers exploited a VPN vulnerability in the group[Ransomware][Service outage]Organizations 1Disclosed 2024-06-10Updated 2026-10-23Shizuoka, Tokyo[Resolved][Severity: Critical]
Takano Sogo Accounting: ransomware puts client data of Tokio Marine group firms and others at risk[Ransomware][Misconfiguration][Data leak]Leaked 27.8KOrganizations 5Disclosed 2024-06-09Updated 2026-10-23Tokyo[Contained][Severity: Critical]
KADOKAWA: ransomware attack on Niconico and other group services[Ransomware][Phishing][Service outage][Data leak][Extortion]Leaked 254.2KOrganizations 2Disclosed 2024-06-06Updated 2026-10-23Fukuoka[Contained][Severity: Moderate]
Shinnihonseiyaku: ransomware encrypts some business data[Ransomware]Organizations 1Disclosed 2024-06-05Updated 2026-10-23Hiroshima, Hyogo, Osaka, Tokyo[Contained][Severity: Critical]
Hirokei: ransomware puts clients' medical data at risk[Ransomware][Misconfiguration][Data leak][Extortion]Leaked 86.9KOrganizations 8Disclosed 2024-06-05Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Karel Capek: personal data of 103,289 members and 58,407 card records may have leaked from its online store[Web app exploit][Data leak]Leaked 103.3KOrganizations 1Disclosed 2024-06-05Updated 2026-10-23Fukuoka[Investigating][Severity: Critical]
Kyuhen: ransomware may have exposed about 374,000 personal records[Ransomware][Data leak]Leaked 374KOrganizations 2Disclosed 2024-06-03Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Tozai Tetsugaku Shoin: card data (18,394 records) and personal data of 50,338 customers may have leaked from the Hakubun Eikodo online shop[Web app exploit][Data leak][Fraud]Leaked 50.3KOrganizations 1Disclosed 2024-05-31Updated 2026-10-23Tokyo[Contained][Severity: Critical]
DMM Bitcoin: 4,502.9 BTC (about ¥48.2 billion) stolen via contractor Ginco; police attribute it to North Korea-linked TraderTraitor[Phishing][Malware][Credential abuse][Financial loss]Organizations 2Disclosed 2024-05-30Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Tully's: intrusion at its online store; payment app tampering may have leaked over 50,000 cards[Web app exploit][Data leak]Leaked 92.7KOrganizations 1Disclosed 2024-05-29Updated 2026-10-23Aichi, Ehime, Kyoto, Osaka, Tokushima, Tokyo, Wakayama[Contained][Severity: Critical]
Iseto: ransomware leaks data of about 3.07 million people from about 100 client organizations[Ransomware][Data leak]Leaked 3.1MOrganizations 13Disclosed 2024-05-24Updated 2026-10-23Nagasaki[Contained][Severity: Critical]
Nagasaki Prefecture Products Promotion Association: card data of 18,746 customers leaked from its e-Nagasaki.com shop[Web app exploit][Data leak]Leaked 60.4KOrganizations 1Disclosed 2024-05-24Updated 2026-10-23Osaka[Contained][Severity: Critical]
Sekisui House: SQL injection on a member site leaks email addresses and passwords[Web app exploit][Misconfiguration][Data leak]Leaked 464.1KOrganizations 1Disclosed 2024-05-21Updated 2026-10-23Okayama[Resolved][Severity: Critical]
Okayama Psychiatric Medical Center: ransomware leaks data of up to about 40,000 patients[Ransomware][Service outage][Data leak]Leaked 40KOrganizations 1Disclosed 2024-05-17Updated 2026-10-23Tokyo[Contained][Severity: Critical]
JF Zengyoren: Gyogyoichi online shop breached; 11,844 card records may have leaked[Web app exploit][Data leak][Service outage]Leaked 21.7KOrganizations 1Disclosed 2024-05-16Updated 2026-10-23Ibaraki[Contained][Severity: Critical]
Joyful Honda: card data (3,958 records) and personal data of 20,132 customers may have leaked from its THE GLOBE·OLD FRIEND shop[Web app exploit][Data leak]Leaked 20.1KOrganizations 1Disclosed 2024-05-16Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
Tomoe Shokai: ransomware via RDP; employee and other personal data at risk[Ransomware][Credential abuse][Service outage][Data leak]Leaked 2.3KOrganizations 2Disclosed 2024-05-14Updated 2026-10-23Osaka[Contained][Severity: Critical]
Kishiwada Sports: card data of 13,960 and personal data of 38,664 KISHISPO customers may have leaked[Web app exploit][Data leak]Leaked 38.7KOrganizations 1Disclosed 2024-05-13Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Biophilia: unauthorized access to its cloud server; data of about 200,000 accounts taken[Intrusion][Data leak]Leaked 198.2KOrganizations 1Disclosed 2024-05-13Updated 2026-10-23Osaka[Contained][Severity: Critical]
Matsui Shuzo: malicious files planted on its online store; card data of 174 customers may have leaked[Web app exploit][Data leak][Fraud]Leaked 174Organizations 1Disclosed 2024-05-02Updated 2026-10-23Aichi[Resolved][Severity: Critical]
Toyoshima: ransomware; attackers got in with obtained IDs and passwords[Ransomware][Credential abuse][Service outage][Data leak]Organizations 1Disclosed 2024-04-30Updated 2026-10-23Miyazaki[Investigating][Severity: Moderate]
Miyazaki Denshi Kiki: ransomware halts its invoicing system[Ransomware][Service outage]Organizations 1Disclosed 2024-04-26Updated 2026-10-23Aichi[Contained][Severity: Critical]
Meira: ransomware; attackers got in with a group company's administrator account[Ransomware][Credential abuse][Service outage][Data leak]Organizations 1Disclosed 2024-04-24Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
SEGA FAVE: email accounts accessed; partner, staff and customer data may have leaked[Intrusion][Data leak]Leaked 10.1KOrganizations 1Disclosed 2024-04-24Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
Wantedly: access setting errors exposed data of 200,578 users on unpublished pages[Misconfiguration][Data leak]Leaked 200.6KOrganizations 1Disclosed 2024-04-23Updated 2026-10-23Tokyo[Investigating][Severity: Moderate]
Endless: LockBit enters through a test account the installer left behindDisclosed 2024-04-19Updated 2026-10-23Tokyo[Contained][Severity: Moderate]
Otsuka: email sent to the wrong address leaked names of 2,687 customers[Misdelivery][Data leak]Leaked 2.7KOrganizations 1Disclosed 2024-04-02Updated 2026-10-23Fukui[Contained][Severity: Critical]
Marukawamiso: card data (5,447 records) and personal data of 89,673 customers may have leaked from its official shop[Web app exploit][Data leak][Fraud]Leaked 89.7KOrganizations 1Disclosed 2024-04-01Updated 2026-10-23Tokyo[Resolved][Severity: Critical]
HOYA: ransomware halts production and leaks personal data[Ransomware][Service outage][Data leak][Extortion]Leaked 3KOrganizations 1Disclosed 2024-03-29Updated 2026-10-23Tokyo[Contained][Severity: Critical]
Workstyle Tech: WelcomeHR server misconfiguration left ID images and other data of 162,830 people open[Misconfiguration][Data leak]Leaked 162.8KOrganizations 1Disclosed 2024-03-26Updated 2026-10-23Tokyo[Investigating][Severity: Moderate]
CRESS TECH: ransomware, likely through a misconfigured UTM device[Ransomware][Misconfiguration][Service outage]Organizations 1Disclosed 2024-03-22Updated 2026-10-23Tokyo[Contained][Severity: Moderate]
Japan Business Data Center: ransomware on the small business subsidy office server destroys and encrypts some data[Ransomware][Service outage]Organizations 2Disclosed 2024-03-15Updated 2026-10-23Kanagawa[Resolved][Severity: Major]
Fujitsu: malware on 49 work PCs may have exfiltrated personal and customer data[Malware][Data leak]Organizations 1Disclosed 2024-03-13Updated 2026-10-23Osaka[Contained][Severity: Major]
FueTrek: ransomware; server data may have leaked[Ransomware][Service outage][Data leak]Organizations 1Disclosed 2024-03-13Updated 2026-10-23Niigata[Investigating][Severity: Moderate]
TeNY: cyberattack encrypts internal PCs and servers; broadcasting not affected[Unknown][Service outage]Organizations 1Disclosed 2024-03-08Updated 2026-10-23Aichi[Investigating][Severity: Moderate]
Aichi Rikuun: ransomware encrypts server data[Ransomware][Service outage]Organizations 1