HackingIdentity (basic)LowContained

Mainline Health Systems Inc

bd_a8b640e79c646007 · schema v1 · pii pii-v2

Severity

Low

Discovered

Apr 10, 2024

Filed

Jun 20, 2025

To disclose

—

Affected

Not disclosed

Linked

6 filings

Confidence

66%

Full breach record for Mainline Health Systems Inc →

Mainline Health Systems, Inc. reported a security incident occurring on or about April 10, 2024, discovered on May 21, 2025. The breach involved unauthorized access to files containing names and addresses (identity_basic). Mainline notified federal law enforcement, engaged external cybersecurity experts, and conducted a manual review. Notices were sent on June 20, 2025, offering 12 months of credit monitoring and ID theft recovery services. No evidence of identity theft was found.

J jump to incidentP pin to compareR raw source

Incident timeline

Apr 10, 2024

Begins

Apr 10, 2024

Discovered

Jun 20, 2025

Filed

This filing is one of 6 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (5) · sorted by filing gap

HHS OCRbd_2f3a0de1cd17c2742025-06-23 · +3dVerified
Massachusetts State AGbd_8f8d9fb358c4917b2025-06-23 · +3dVerified
Maine State AGbd_f84aac6a930bd29b2025-06-23 · +3dVerified
New Hampshire State AGbd_261065496c6ad4cb2025-06-24 · +4dVerified

Show 1 more filing ↓up to 10d gap

Texas State AGbd_4b8f3ae79ac45cb02025-06-30 · +10dVerified

Name: Mainline Health Systems Inc
norm: mainline health

Name: Mainline Health Systems Inc
norm: mainline health

Discovered: Apr 10, 2024
Breach occurred: Apr 10, 2024
Undetected for: 0 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jun 20, 2025
Affected individuals: Not disclosed
Data types: Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Initial access: valid_credentials

During the incident: Notified federal law enforcement of the incident
Engaged external cybersecurity experts
Conducted a manual review of the impacted files
Reviewing its existing policies and training protocols relating to data protection
Enhancing security measures and monitoring tools
Changes made: Reviewing its existing policies and training protocols relating to data protection
Enhancing security measures and monitoring tools
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 · 6 filings · 6 states

View merged incident ↗

Nebraska State AGJun 20 · first · this page

HHS OCR+3d

Massachusetts State AG+3d

Maine State AG+3d

New Hampshire State AG+4d

Texas State AG+10d

Pattern: first filing Jun 20 (NE), last Jun 30 (TX) — a 10-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

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/53b94bf8-a131-4083-b548-64c5030c5331.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jun 20, 2025
Raw hash: 4fbf266b99c1ae6720cc2d68ffbca4a17b326430402f2bcd68ad99ad7ea9ab88

Linked disclosures

Regulatory filings (5) · sorted by filing gap

Reporting entityMainline Health Systems Inc

Victim entityMainline Health Systems Inc

Incidentdiscovered Apr 10, 2024

Stated responseNotified federal law enforcement of the incident

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancenebraska.gov