Mayfield Clinic
Disclosed Apr 23, 201623,341 affectedConfirmed
An unauthorized person sent a fraudulent email with an attachment that triggered a download of a ransomware virus to 23,341 email addresses held by the covered entity’s (CE’s) business associate (BA) on its behalf. The protected health information (PHI) involved in the breach included email addresses. The CE sent an email notification to affected individuals on the day of the incident and sent another email notification two days later. The CE provided breach notification to HHS, affected individuals, and the media and also posted substitute notice on its web site. Following the breach, the CE assessed system controls, provided anti-scanning updates to its employees’ email, deleted the email addresses it maintained on its BA’s systems, and put a hold on the future electronic distribution of newsletters. OCR obtained written assurances that the CE implemented the corrective actions listed above.
What is known
| People affected | 23,341 (as reported to HHS) |
|---|---|
| Disclosed | Apr 23, 2016 |
| Attack | Hacking |
| Data exposed | NamesHealth |
| Sector | Healthcare · US |
| Status | Confirmed |
Sources
Notices filed
History of this record
First seen 2026-09-25 (HHS archive), confirmed by HHS OCR. Record counts are as reported. Not legal advice.