Summary
- Environment: Hospital network files
- Operational impact: Personal and health information potentially accessed
- Financial impact: No incident cost publicly quantified
- Record status: Developing record. Reviewed November 6, 2026; updated as evidence emerges.
What happened
Hoag Memorial Hospital Presbyterian detected suspicious network activity on October 8, 2026. Its investigation found that certain files may have been accessed without authorization. [1]
Impact
The potentially affected files contained personal or protected health information. The public sample identifies names but leaves the other recipient-specific data elements unspecified; it gives no affected-person total. [1]
Timeline
Suspicious network activity detected
Suspicious network activity detected, as described in the incident notice.
[1]Personal-information review completed
Personal-information review completed, as described in the incident notice.
[1]Notification letter dated
Notification letter dated, as described in the incident notice.
[1]Briefing updated
This briefing was last reviewed and updated on November 6, 2026.
Threat Group & Attack Vector
The reviewed notice does not establish the initial access method.
Actors
- No threat actor group has been identified in the reviewed public evidence.
TTPs
- No specific MITRE ATT&CK technique is currently mapped for this case.
Response
Hoag engaged independent forensic experts, secured its environment and added safeguards. An October 25 file review identified potentially affected personal information, and its November 4 letter offered credit monitoring and identity protection. [1]