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Incident

MercyOne Clinton Medical Center

Incident posture

Attack window
Mar 2023
Location
United States of America
Status
Historical
CIA posture
Available to members
Updated
2025-12-16 00:00

Linked entities

Victim
MercyOne Clinton Medical Center
Threat actors
1 actor
Sources
2 sources

Timeline

Occurred
Mar 2023
Discovered
Pending
Disclosed
Pending
Resolved
Pending

Summary

MercyOne Clinton Medical Center experienced a cyberattack involving unauthorized network access over a month-long period, disrupting operations but not affecting patient care. The breach compromised sensitive data for 20,865 individuals, including personal identifiers, medical details, financial information, and insurance data. While no misuse was confirmed, the organization restored systems from backups but acknowledged unrecoverable data loss affecting patient reports and documents. Forensic analysis was conducted, technical safeguards were enhanced, and impacted individuals were offered credit monitoring and identity protection services.

Motives

Detailed motive labels are available to members.

3 motives

TTPs

Detailed technique labels are available to members.

1 technique

Description

MercyOne Clinton Medical Center experienced a network disruption on April 4, 2023, prompting an immediate investigation with third-party forensic specialists. The investigation revealed unauthorized access to certain portions of the clinic's network between March 7, 2023, and April 4, 2023. The breach did not disrupt patient care but necessitated restricted system access during remediation efforts. MercyOne initiated secure restoration of its network while conducting a review to determine the specifics of compromised data. Although the forensic analysis remained ongoing as of the May 12, 2023, notification, preliminary findings confirmed the exposure of patient information including names, addresses, dates of birth, driver’s license or state identification numbers, Social Security numbers, financial account details, medical record numbers, Medicare/Medicaid identifiers, treatment or diagnosis information, prescription data, billing records, and health insurance details. The incident affected 20,865 individuals across MercyOne’s clinics in Clinton, Iowa. Data had to be restored from backups, resulting in an inability to fully recover some patient information contained in reports and documents, which may have included the same categories of sensitive data.

MercyOne confirmed no evidence of actual misuse of the exposed information but notified affected individuals out of caution. The response included engaging third-party specialists to restore network security, implementing additional technical safeguards, and reviewing internal data protection policies. Efforts to recreate unrecoverable data were underway. The clinic offered 24-month complimentary credit monitoring and identity protection services through a dedicated assistance line. Patients were advised to review healthcare statements for inaccuracies and monitor financial accounts for suspicious activity. MercyOne recommended contacting credit bureaus to place fraud alerts or credit freezes and provided contact details for the Federal Trade Commission and state attorneys general for identity theft reporting. Restoration of the network continued post-incident to minimize service interruptions while preserving patient care operations.

Sources

Sources available to members: 2 sources.

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