{ "id": "39ebd686-7be0-499d-a398-cc695a98a39f", "created_at": "2026-04-06T00:08:52.498378Z", "updated_at": "2026-04-10T03:27:23.767474Z", "deleted_at": null, "sha1_hash": "f04f413fde80a572745e8179cec726bb49a37c82", "title": "Nippon Medical School Musashi Kosugi Hospital Data Breach Claimed by NetRunnerPR", "llm_title": "", "authors": "", "file_creation_date": "0001-01-01T00:00:00Z", "file_modification_date": "0001-01-01T00:00:00Z", "file_size": 551376, "plain_text": "Nippon Medical School Musashi Kosugi Hospital Data Breach\r\nClaimed by NetRunnerPR\r\nBy Written by\r\nPublished: 2026-02-12 · Archived: 2026-04-02 11:50:45 UTC\r\nA threat actor operating under the name “NetRunnerPR” has claimed responsibility for a cyberattack against\r\nNippon Medical School Musashi Kosugi Hospital in Japan, alleging the exfiltration of 131,135 patient records.\r\nThe claim was posted on a cybercrime forum on February 11, 2026, and includes what appears to be sample data\r\nintended to validate the breach.\r\nHospitals \u0026 Treatment Centers\r\nAt the time of writing, the alleged Nippon Medical School Musashi Kosugi Hospital data breach remains\r\nunverified. No official confirmation has been issued by the hospital, regulators, or Japanese authorities.\r\nBreach Notification Service\r\nWhat the Threat Actor Claims\r\nAccording to the forum post, NetRunnerPR states that the hospital’s network was successfully breached and that\r\n131,135 unique patient PII records were extracted. The actor further claims that an additional 20,000 records will\r\nhttps://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/\r\nPage 1 of 4\n\nbe released publicly on February 16, 2026, if certain undisclosed conditions are not met.\r\nThe dataset is described as containing personally identifiable information including:\r\nPatient ID numbers\r\nFull names and alias names\r\nSex and date of birth\r\nResidential addresses\r\nPhone numbers\r\nEmergency contact details\r\nThe actor also referenced a hospital director and family members in the post, a tactic sometimes used in extortion\r\ncampaigns to increase pressure on victims.\r\nAnalysis of the Sample Data\r\nThe forum listing includes what appears to be a partial CSV-style export. The visible header fields suggest\r\nstructured database extraction rather than unorganized document theft. The column naming conventions indicate\r\nstandardized internal record formatting.\r\nData Backup Solutions\r\nHowever, the presence of sample data alone does not confirm the scope, authenticity, or recency of the dataset.\r\nWithout independent forensic validation, it remains unclear whether:\r\nThe records are recent or historical\r\nThe dataset is complete or partial\r\nThe information originates from internal systems or third-party providers\r\nThe data has been altered or combined from previous breaches\r\nWho Is NetRunnerPR?\r\nNetRunnerPR appears to be a relatively new account on the forum where the claim was posted. As of the time of\r\npublication, the account shows limited activity history and minimal reputation metrics.\r\nThere is no publicly documented history tying NetRunnerPR to major ransomware operations or previously\r\nconfirmed breaches. This lack of established track record introduces uncertainty regarding the credibility of the\r\nclaim.\r\nThreat actors frequently use newly created accounts to post high-profile breach claims, particularly in healthcare\r\nand education sectors, where sensitive data increases leverage.\r\nHospitals \u0026 Treatment Centers\r\nWhy Healthcare Breaches Are High Impact\r\nhttps://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/\r\nPage 2 of 4\n\nHealthcare institutions are consistently among the most targeted sectors in cybercrime campaigns. Patient data is\r\nconsidered highly valuable because it often includes comprehensive identity profiles that can be used for fraud,\r\nidentity theft, insurance abuse, and social engineering attacks.\r\nMedical records typically contain stable identifiers such as full legal names, dates of birth, government-issued\r\nIDs, and long-term contact information. Unlike passwords, this type of data cannot easily be changed once\r\nexposed.\r\nIn Japan, healthcare organizations are subject to strict privacy and data protection requirements. If confirmed, the\r\nincident could trigger regulatory scrutiny and mandatory disclosure obligations under Japanese data protection\r\nframeworks.\r\nPossible Attack Scenarios\r\nAt this stage, the intrusion vector remains unknown. Common entry points for hospital network compromises\r\ninclude:\r\nPhishing campaigns targeting staff\r\nCompromised remote desktop services\r\nUnpatched vulnerabilities in web-facing systems\r\nThird-party vendor access abuse\r\nRansomware affiliate activity\r\nThe forum post does not explicitly mention ransomware encryption, suggesting the possibility of a data\r\nexfiltration-only operation. However, without official confirmation, the exact method of compromise remains\r\nspeculative.\r\nThe Threat of Staggered Releases\r\nThe actor’s statement that 20,000 additional records will be released on February 16 follows a pattern commonly\r\nseen in extortion campaigns. Staggered release threats are designed to increase urgency and pressure organizations\r\ninto negotiations.\r\nAntivirus \u0026 Malware\r\nSuch tactics are frequently used in double extortion schemes, where attackers both encrypt systems and threaten\r\npublic data exposure. However, no evidence currently confirms that encryption occurred in this case.\r\nWhat We Do Not Yet Know\r\nSeveral key questions remain unanswered:\r\nHas Nippon Medical School Musashi Kosugi Hospital confirmed a breach?\r\nHave Japanese regulators been notified?\r\nIs the dataset authentic and complete?\r\nWas ransomware deployed, or was this purely data theft?\r\nhttps://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/\r\nPage 3 of 4\n\nAre the affected individuals aware of potential exposure?\r\nUntil independent verification or official disclosure occurs, the claim should be treated as an alleged breach rather\r\nthan a confirmed incident.\r\nCurrent Status\r\nAs of February 11, 2026, the breach claim remains pending verification. No official public statements have been\r\nreleased by the hospital.\r\nData Backup Solutions\r\nBotcrawl will continue monitoring developments related to the alleged Nippon Medical School Musashi Kosugi\r\nHospital data breach and will update this article as additional verified information becomes available.\r\nSource: https://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/\r\nhttps://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/\r\nPage 4 of 4", "extraction_quality": 1, "language": "EN", "sources": [ "MISPGALAXY", "Malpedia" ], "references": [ "https://botcrawl.com/nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr/" ], "report_names": [ "nippon-medical-school-musashi-kosugi-hospital-data-breach-claimed-by-netrunnerpr" ], "threat_actors": [ { "id": "e9d5d63a-ef3b-4d4e-b044-e4dad4cde45f", "created_at": "2026-03-08T02:00:03.480481Z", "updated_at": "2026-04-10T02:00:03.986404Z", "deleted_at": null, "main_name": "NetRunnerPR", "aliases": [], "source_name": "MISPGALAXY:NetRunnerPR", "tools": [], "source_id": "MISPGALAXY", "reports": null } ], "ts_created_at": 1775434132, "ts_updated_at": 1775791643, "ts_creation_date": 0, "ts_modification_date": 0, "files": { "pdf": "https://archive.orkl.eu/f04f413fde80a572745e8179cec726bb49a37c82.pdf", "text": "https://archive.orkl.eu/f04f413fde80a572745e8179cec726bb49a37c82.txt", "img": "https://archive.orkl.eu/f04f413fde80a572745e8179cec726bb49a37c82.jpg" } }