Marshfield Clinic Health System experienced a cybersecurity breach where an unauthorized individual accessed its network and potentially exfiltrated sensitive personal and health data. The compromised information includes personally identifiable details (PII) such as names, addresses, phone numbers, dates of birth, insurance IDs, medical record numbers, and protected health information (PHI) like treatment/diagnosis records, lab results, and medication data. The breach affects an unknown number of individuals, exposing them to risks of identity theft, fraud, or misuse of medical history. Legal investigations are underway, with law firm Lynch Carpenter, LLP reviewing claims for potential compensation on behalf of impacted parties. The incident underscores vulnerabilities in healthcare data security, raising concerns over patient privacy and regulatory compliance.
TPRM report: https://www.rankiteo.com/company/marshfield-clinic-health-system
"id": "mar5502855112125",
"linkid": "marshfield-clinic-health-system",
"type": "Breach",
"date": "11/2025",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': 'Unknown number of individuals',
'industry': 'Healthcare',
'location': 'Pittsburgh, PA (HQ), with operations in '
'Wisconsin and broader U.S.',
'name': 'Marshfield Clinic Health System',
'type': 'Healthcare Provider'}],
'customer_advisories': 'Individuals impacted may be entitled to compensation; '
'advised to contact Lynch Carpenter, LLP for case '
'review.',
'data_breach': {'data_exfiltration': "Possible (records 'may have been "
"acquired')",
'number_of_records_exposed': 'Unknown',
'personally_identifiable_information': ['Names',
'Addresses',
'Phone numbers',
'Dates of birth',
'Insurance ID numbers',
'Medical record '
'numbers',
'Dates of service',
'Treatment/diagnosis '
'information',
'Lab results',
'Medications'],
'sensitivity_of_data': 'High (includes medical and insurance '
'details)',
'type_of_data_compromised': ['PII (Personally Identifiable '
'Information)',
'PHI (Protected Health '
'Information)']},
'date_publicly_disclosed': '2025-11-20',
'description': 'An unauthorized person gained access to Marshfield Clinic '
'Health System’s network and may have acquired records '
'containing personally identifiable information (PII) and '
'protected health information (PHI), including names, '
'addresses, phone numbers, dates of birth, insurance ID '
'numbers, medical record numbers, dates of service, '
'treatment/diagnosis information, lab results, and '
'medications. The exact number of affected individuals is '
'unknown.',
'impact': {'brand_reputation_impact': 'Potential (under investigation)',
'data_compromised': ['Personally Identifiable Information (PII)',
'Protected Health Information (PHI)'],
'identity_theft_risk': 'High (PII and PHI exposed)',
'legal_liabilities': 'Potential (class action investigation by '
'Lynch Carpenter, LLP)',
'systems_affected': ['Network']},
'initial_access_broker': {'high_value_targets': ['PII', 'PHI']},
'investigation_status': 'Ongoing (legal investigation by Lynch Carpenter, '
'LLP)',
'references': [{'date_accessed': '2025-11-20',
'source': 'Globe Newswire Press Release',
'url': 'https://www.marshfieldclinic.org/'},
{'source': 'Lynch Carpenter, LLP Investigation Page',
'url': 'https://www.lynchcarpenter.com/'}],
'regulatory_compliance': {'legal_actions': 'Class action investigation '
'initiated by Lynch Carpenter, '
'LLP'},
'response': {'communication_strategy': 'Public disclosure via Globe Newswire; '
'legal investigation announced by '
'Lynch Carpenter, LLP'},
'threat_actor': 'Unauthorized person',
'title': 'Marshfield Clinic Health System Data Breach',
'type': 'Data Breach'}