MalwareHealthcareHealthcareRansomwareData EncryptedData ExfiltratedCustomer Data InvolvedIdentity (basic)Government IDHealth (basic)Financial accountMediumContained

Horizon Behavioral Health

bd_494ebdd5f2841ce4 · schema v1 · pii pii-v2

Severity

Medium

Discovered

Mar 16, 2025

Filed

Apr 21, 2025

To disclose

—

Affected

Not disclosed

Linked

5 filings

Confidence

66%

Full breach record for Horizon Behavioral Health →

Horizon Behavioral Health notified Nebraska AG of a ransomware incident discovered on March 16, 2025, with unauthorized access occurring between March 13 and 16, 2025. The breach impacted patient demographic, government ID, clinical, and insurance data. Horizon engaged law enforcement (FBI, CISA) and forensic experts, providing complimentary identity monitoring to affected individuals.

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Incident timeline

undetected · 3 days

Mar 13, 2025

Begins

Mar 16, 2025

Discovered

Apr 21, 2025

Filed

This filing is one of 5 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (4) · sorted by filing gap

Vermont State AGbd_225fc4e0b0d887932025-04-21Candidate
HHS OCRbd_87431939e0eabf122025-04-21Candidate
Montana State AGbd_ba25fb5419d6a0062025-04-21Verified
Massachusetts State AGbd_c52606e3518997232025-04-21Verified

Name: Horizon Behavioral Health
norm: horizon behavioral health

Name: Horizon Behavioral Health
norm: horizon behavioral health
Industry: Healthcarellm

Discovered: Mar 16, 2025
Breach occurred: Mar 13, 2025 – Mar 16, 2025
Undetected for: 3 daysoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: Not disclosed
Data types: Identity (basic)Government IDHealth (basic)Financial account
Attack vector: Ransomware
MITRE ATT&CK: T1486 Data Encrypted for ImpactT1119 Automated Collection
Threat actor: ExternalFinancial
Regulator citations: Notified state and federal law enforcement, including the FBI’s Cyber Crimes Division, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA), and the Cyber Fusion Center of the Virginia State Police

During the incident: Notified state and federal law enforcement, including the FBI’s Cyber Crimes Division, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA), and the Cyber Fusion Center of the Virginia State Police
Engaged outside cybersecurity experts to investigate this event
Arranged to provide complimentary identity monitoring for any individuals with data potentially implicated by this incident
Reviewed our system security and taken steps to increase that security going forward
Changes made: Reviewed our system security and taken steps to increase that security going forward
Source: Quoted from the filing itself, not independently verified.

Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 5 filings · 5 states

View merged incident ↗

Vermont State AGApr 21 · first

HHS OCRApr 21 · first

Montana State AGApr 21 · first

Massachusetts State AGApr 21 · first

Nebraska State AGApr 21 · 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://nebraska.gov/ago/data-breach/documents/19f503cc-a408-425e-94bd-d09b26bc3bd2.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 21, 2025
Raw hash: 7a30f3970a4b695910e0403a8fe9dabc664384b538f8459d650828f1b108b5ef

Linked disclosures

Regulatory filings (4) · sorted by filing gap

Reporting entityHorizon Behavioral Health

Victim entityHorizon Behavioral Health

Incidentdiscovered Mar 16, 2025

Stated responseNotified state and federal law enforcement, including the FBI’s Cyber Crimes Division, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA), and the Cyber Fusion Center of the Virginia State Police

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancenebraska.gov