McLaren Health Care
Disclosed Jun 20, 20251 year ago743,131 affectedConfirmed
INC ransomware attack on McLaren exposed data of 743,131 patients
McLaren Health Care began notifying 743,000 patients that a July 2024 INC ransomware attack, discovered August 5, 2024, exposed their data; the investigation finished May 5, 2025.
What is known
| People affected | 743,131 (as reported to HHS) |
|---|---|
| Disclosed | Jun 20, 2025 |
| Discovered | Aug 5, 2024 |
| Happened | Jul 17, 2024 |
| Attack | Ransomware |
| Data exposed | Names, Health, Social Security numbers, Insurance, Dates of birth, Other |
| Sector | Healthcare · US |
| Status | Confirmed |
Sources
| Source | |
|---|---|
| HHS OCR breach report: McLaren Health Care (Healthcare Provider, MI)ocrportal.hhs.gov · Official notice | Official notice |
| McLaren Health Care says data breach impacts 743,000 patientsbleepingcomputer.com · News | News |
| June 2025 Healthcare Data Breach Reporthipaajournal.com · News | News |
| Vermont Attorney General: 2025-06-20 McLaren Health Care Data Breach Notice to Consumersago.vermont.gov · Official notice | Official notice |
| Indiana Attorney General 2025 data breach report: McLaren Health Carein.gov · Official notice | Official notice |
Notices filed
| Where | Filed | People |
|---|---|---|
| Researchtotal | Jun 20, 2025 | 743,131 |
| Vermont AGresidents of VT | Jun 20, 2025 | |
| Indiana AGresidents of IN | Jun 20, 2025 | 530 |
| HHS OCRtotal | Jun 24, 2025 | 743,131 |
Other breaches at McLaren Health Care
| Breach | Affected | ||||
|---|---|---|---|---|---|
| Disclosed Oct 20, 2023Oct 20, 20232 years agoHacking | Oct 20, 20232 years ago | Hacking | Healthcare | Confirmed | 2.1M |
| Disclosed Jul 16, 2021Jul 16, 20215 years agoHacking | Jul 16, 20215 years ago | Hacking | Healthcare | Confirmed | 65K |
History of this record
- 2026-09-25 · occurred: empty to 2024-07-17 · backfill source
- 2026-09-25 · source: empty to https://ago.vermont.gov/document/2025-06-20-mclaren-health-care-data-breach-notice-consumers · backfill source
- 2026-09-25 · attack: hacking to ransomware · seed source
- 2026-09-25 · data_types: ["names","health"] to ["names","health","ssn","insurance","dob","other"] · seed source
- 2026-09-25 · disclosed: 2025-06-24 to 2025-06-20 · seed source
- 2026-09-25 · discovered: empty to 2024-08-05 · seed source
- 2026-09-25 · summary: empty to McLaren Health Care began notifying 743,000 patients that a July 2024 INC ransomware attack, discovered August 5, 2024, exposed their data; the investigation finished May 5, 2025. · seed source
- 2026-09-25 · title: empty to INC ransomware attack on McLaren exposed data of 743,131 patients · seed source
- 2026-09-25 · added · backfill source
First seen 2026-09-25 (HHS OCR), confirmed by HHS OCR. Record counts are as reported. Not legal advice.