MalwareHealthcareFinancial ServicesHealthcareRansomwareData ExfiltratedData EncryptedIdentity (basic)Government IDMediumContained

Horizon Healthcare RCM

bd_00ff9a47dfc272c4 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Dec 27, 2024

Filed

Nov 26, 2025

To disclose

48 weeks

Affected

Not disclosed

Linked

4 filings

Confidence

64%

Full breach record for Horizon Healthcare RCM →2 incidents on file

Horizon Healthcare RCM notified Vermont AG of a ransomware incident occurring Dec 26-27, 2024. Files were encrypted and copied. Data included names and government IDs. Horizon restored systems, had attacker delete data, and offers Kroll identity monitoring. No specific count disclosed.

J jump to incidentP pin to compareR raw source

Vermont clock✗ VT AG >45 bday48 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 1 days

discovery → filing · 48 weeks / 334 days

Dec 26, 2024

Begins

Dec 27, 2024

Discovered

Nov 26, 2025

Filed

vs. sector median

+35 wks slower

This filing is one of 4 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (3) · sorted by filing gap

Maine State AGbd_24c4025ca3ca22ff2025-11-26Candidate
Montana State AGbd_c5493de054e7d7522025-11-26Candidate
New Hampshire State AGbd_ef67249e664d42272025-11-26Verified

Name: Horizon Healthcare RCM
norm: horizon healthcare rcm

Name: Horizon Healthcare RCM
norm: horizon healthcare rcm
Industry: HealthcarellmFinancial Servicesllm

Discovered: Dec 27, 2024
Breach occurred: Dec 26, 2024 – Dec 27, 2024
Undetected for: 1 dayoccurrence → discovery
Materiality determined: Nov 26, 2025
Notification sent: Nov 26, 2025
Affected individuals: Not disclosed
Data types: Identity (basic)Government ID
Attack vector: Ransomware
MITRE ATT&CK: T1486 Data Encrypted for ImpactT1041 Exfiltration Over C2 Channel
Threat actor: ExternalFinancial
Regulator citations: Filed notice with Vermont Attorney General

During the incident: Securely restored systems
Arranged for the party responsible to delete the copied information
Providing notice of this event to individuals
Providing free resources and guidance
Implemented additional technical measures and processes to further enhance the company’s security
Secured the services of Kroll to provide identity monitoring
Changes made: Implemented additional technical measures and processes to further enhance the company’s security
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 48 weeks(334 days from discovery to filing)
Compliance flags: VT AG >45 bday
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 4 filings · 4 states

View merged incident ↗

Maine State AGNov 26 · first

Montana State AGNov 26 · first

New Hampshire State AGNov 26 · first

Vermont State AGNov 26 · first · this page

Evidence ladder

Leak-site claim

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filingThis record

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

Source URL: https://ago.vermont.gov/document/2025-11-26-horizon-healthcare-rcm-data-breach-notice-consumers
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Nov 26, 2025
Raw hash: c83d215c8904da9f0305ae9036a2afdd3adae552f397536c37bc7a3e8d84735f

Linked disclosures

Regulatory filings (3) · sorted by filing gap

Reporting entityHorizon Healthcare RCM

Victim entityHorizon Healthcare RCM

Incidentdiscovered Dec 27, 2024

Stated responseSecurely restored systems

ComplianceVT AG >45 bday

Extraction provenanceno artifact recorded

Source provenanceago.vermont.gov