OSF Healthcare 2023 Data Breach
Healthcare provider · Hospital and clinical services · Integrated health system · USA
OSF HealthCare Catholic Health System Breach (2023): Patient Medical Diagnoses & SSN Exposed
Catholic healthcare system operating hospitals and clinics.
Confirmed · ObscureIQ Intelligence
Breach Risk Index i
58/100
Lower riskHigher risk
Moderate: notable exposure with meaningful misuse potential.
Data Sensitivity i
ElevatedExposed data raises the risk of fraud, targeting, and impersonation. Proactive steps are warranted.
520KRecords
2023Year
The Breach Risk Index (BRI) is a proprietary 0–100 score rating how dangerous a breach is right now, based on how recently the data has been circulating on the dark web and how valuable it is to attackers.
Crucial data exposed
SSNSocial Security Number
PHI / MedicalMedical Diagnosis
AddressPhysical address
Breach Summary
OSF HealthCare data was exposed in the 2023 Cl0p MOVEit campaign via its vendor Welltok, which used the vulnerable MOVEit Transfer platform. About 520,000 records were affected, including names, mailing and email addresses, phone numbers, dates of birth, genders, Social Security numbers, and National Provider Identifier (NPI) numbers.
Full threat analysis, exploitation vectors, and principal guidance below.
11 additional sections · verified field analysis · defensive doctrine
Querying breach corpus…
Cross-referencing exposed field types…
Resolving threat-actor attribution…
Compiling principal risk advisory…
520K records analyzed
About OSF Healthcare
OSF HealthCare is a US Catholic health system operating hospitals and clinics across Illinois and Michigan.
Why They Hold Your Data
Integrated healthcare systems collect patient identity, medical records, billing data, insurance information, and clinical interaction data across hospital networks.
Data Points Exposed
6 verified field types
Email Address
Full Name
Medical Diagnosis Critical
Phone Number
Physical address High
Social Security Number Critical
Breach Impact
SSNs combined with full identity and health-adjacent identifiers create serious identity-fraud and medical-fraud risk for patients.
Exploitation & Downstream Threats
• Identity theft and synthetic identity construction using government-issued IDs | • SIM swap attacks where phone numbers are present | • Targeted phishing campaigns using exposed email addresses | • Doxxing risk from physical address exposure | • Medical identity fraud or insurance abuse using health data
Principal Risk Advisory
What this means for a principal
A healthcare-linked breach: exposure ties a named individual to a provider relationship and, where clinical or insurance data is present, to conditions and treatment. For a high-profile principal this is targeting-grade, not merely identity-theft-grade: the combination lets an adversary locate, impersonate, or pressure the principal with little additional work.
What You Should Do
- Freeze credit at all three bureaus and monitor for new-account and tax-refund fraud.
- Treat the home address as exposed: review mail and package handling and physical-security routines, and brief household staff to verify unusual requests.
- Guard against SIM-swap and vishing: add a carrier port-out PIN and verify any 'support' calls independently.
- Do not use unofficial 'am I affected' lookups; several are themselves harvesting operations.
How ObscureIQ Can Help
- Corpus confirmation: determine whether and where the principal (plus household and staff) appear in this dataset and which specific fields are exposed for them.
- Exposure mapping and footprint neutralization: cross-reference against broker-available data and suppress still-removable elements, prioritizing address and phone, since this record re-seeds broker networks.
- ThreatWatch tuned to this incident's identifiers and misuse pattern (impersonation and targeting patterns, not generic credential monitoring).
C/
Threat Actor: Cl0p / CL0PConfidence: High
Motivation: Financial extortion
A mature extortion group associated in public reporting with TA505 and FIN11-linked ecosystems. Cl0p is known for mass exploitation of managed file transfer products, including the 2023 MOVEit Transfer campaign exploiting CVE-2023-34362.
This breach is linked to the MOVEit / Cl0p (2023) campaign (2023 related breaches tracked by ObscureIQ). See the full campaign analysis →
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