HackingHealthcareHealthcareCustomer Data InvolvedIdentity (basic)HighContained

Mainline Health Systems Inc

bd_f84aac6a930bd29b · schema v1 · pii pii-v1

Severity

High

Discovered

May 21, 2025

Filed

Jun 23, 2025

To disclose

5 weeks

Affected · nationwide

101,1041 in this filing

Linked

6 filings

Confidence

66%

Full breach record for Mainline Health Systems Inc →

Mainline Health Systems Inc reported an external system breach (hacking) occurring on April 10, 2024, discovered on May 21, 2025. The incident affected 101,104 individuals, including 1 Maine resident. Data types included names and addresses. The company engaged external cybersecurity experts, notified law enforcement, and offered 12 months of credit monitoring services to affected individuals.

J jump to incidentP pin to compareR raw source

Maine clockDiscovered May 21, 2025 → Filed with AG Jun 23, 202533d ⏱ ME AG >30d5 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 · 406 days

discovery → filing · 5 weeks / 33 days

Apr 10, 2024

Begins

May 21, 2025

Discovered

Jun 23, 2025

Filed

vs. sector median

8 wks faster

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_2f3a0de1cd17c2742025-06-23Verified
Massachusetts State AGbd_8f8d9fb358c4917b2025-06-23Verified
New Hampshire State AGbd_261065496c6ad4cb2025-06-24 · +1dVerified
Nebraska State AGbd_a8b640e79c6460072025-06-20 · +3dVerified

Show 1 more filing ↓up to 7d gap

Texas State AGbd_4b8f3ae79ac45cb02025-06-30 · +7dVerified

Name: Mainline Health Systems Inc
norm: mainline health
Industry: Healthcare

Name: Mainline Health Systems Inc
norm: mainline health
Industry: Healthcare
Industry: Healthcarellm

Discovered: May 21, 2025
Breach occurred: Apr 10, 2024
Undetected for: 406 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jun 20, 2025
Affected individuals: 101,104state + nationwide
Data types: Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1190 Exploit Public-Facing Application
Threat actor: External
Regulator citations: Filed notification with Maine Attorney General
Initial access: exploit_public_facing

During the incident: Notified federal law enforcement of the incident
Engaged external cybersecurity experts
Conducted a manual review of the impacted files
Changes made: Reviewing its existing policies and training protocols relating to data protection
Enhancing security measures and monitoring tools to further mitigate risks of this nature
Continually evaluate and modify our practices and internal controls to enhance the security and privacy of your protected personal information
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 5 weeks(33 days from discovery to filing)
Compliance flags: ME AG >30d · 33d
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.
Clock breakdown: Statute Window Elapsed Threshold Status
Maine
Discovered: May 21, 2025
→ Filed with AG: Jun 23, 2025
33d 30 days (soft) ME AG >30d

Statute	Window	Elapsed	Threshold	Status
Maine	Discovered: May 21, 2025 → Filed with AG: Jun 23, 2025	33d	30 days (soft)	ME AG >30d

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 6 filings · 6 states

View merged incident ↗

Nebraska State AGJun 20 · first

HHS OCR+3d

Massachusetts State AG+3d

Maine State AG+3d · this page

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://www.maine.gov/agviewer/content/ag/985235c7-cb95-4be2-8792-a1252b4f8318/780cf6d5-bc22-4ee0-b46a-1b360475f087.html
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jun 23, 2025
Raw hash: 3b99fa1fde9ddf410bd7e499ce5e8652d2221e8ce92b453a27a28be8096e3f6a

Linked disclosures

Regulatory filings (5) · sorted by filing gap

Reporting entityMainline Health Systems Inc

Victim entityMainline Health Systems Inc

Incidentdiscovered May 21, 2025

Stated responseNotified federal law enforcement of the incident

ComplianceME AG >30d

Extraction provenanceno artifact recorded

Source provenancewww.maine.gov