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MSK Group

Disclosed May 22, 2018566,236 affectedConfirmed

Official notice

The covered entity (CE), MSK Group PC, discovered on May 7, 2018, that ransomware blocked access to its computer servers which the contained electronic protected health information (ePHI) of 566,236 former and current patients. The ePHI potentially affected included demographic, clinical, and health insurance information. The CE was unable to determine whether ePHI had been copied or transferred outside of the network. The CE timely performed its breach notification obligations. In response to the breach, the CE engaged an information technology firm to continuously monitor its information systems and respond to suspicious activity. The CE also retrained its workforce and implemented substantial technical safeguards, including upgrading firewall protections, reconfiguring servers, and restricting remote access. OCR obtained assurances that the CE implemented the corrective actions listed above and performed its notification obligations.

What is known

People affected566,236 (as reported by the organization)
DisclosedMay 22, 2018
HappenedMay 7, 2018
AttackHacking
Data exposedNamesSocial Security numbersHealthInsuranceEmailsPhone numbersAddresses
SectorHealthcare · US
StatusConfirmed

Sources

Notices filed

History of this record
sector2026-09-25
other to healthby backfillSource
attack2026-09-25
unknown to hackingby backfillSource
disclosed2026-09-25
2018-07-05 to 2018-05-22by backfillSource
summary2026-09-25
empty to The covered entity (CE), MSK Group PC, discovered on May 7, 2018, that ransomware blocked access to its computer servers which the contained electronic protected health information (ePHI) of 566,236 former and current patients. The ePHI potby backfillSource
data_types2026-09-25
[] to ["names","ssn","health","insurance","emails","phone","addresses"]by backfillSource
records_basis2026-09-25
empty to organizationby backfillSource
records2026-09-25
empty to 566236by backfillSource
Added2026-09-25
First recordedby backfillSource

First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.

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