HackingHealthcareHealthcareStolen CredentialsTargetedPIIIdentity (basic)LowContained

Cornerstone Healthcare Group Management Services LLC

bd_200de4f01295e185 · schema v1 · pii pii-v1

Severity

Low

Discovered

Dec 15, 2023

Filed

Jul 1, 2024

To disclose

28 weeks

Affected

7state residents only

Linked

4 filings

Confidence

66%

Full breach record for Cornerstone Healthcare Group Management Services LLC →3 incidents on file

Cornerstone Healthcare Group Management Services LLC experienced a data breach on December 19, 2023, involving unauthorized access to personal information of individuals associated with supported healthcare facilities. The incident was detected in mid-December 2023. The company engaged cybersecurity firms and law enforcement, and is offering credit monitoring services.

J jump to incidentP pin to compareR raw source

Incident timeline

Dec 19, 2023

Begins

Jul 1, 2024

Filed

vs. sector median

+16 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

Vermont State AGbd_9098338e61d3b15b2024-07-01Verified
Massachusetts State AGbd_09280395ee87b7fb2024-07-02 · +1dVerified
New Hampshire State AGbd_097148949845f28d2024-07-08 · +7dVerified

Name: Cornerstone Healthcare Group Management Services LLC
norm: cornerstone healthcare group management

Name: Cornerstone Healthcare Group Management Services LLC
norm: cornerstone healthcare group management
Industry: Healthcarellm

Discovered: Dec 15, 2023
Breach occurred: Dec 19, 2023
Materiality determined: —
Notification sent: —
Affected individuals: 7state-resident count only
Data types: PIIIdentity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Initial access: valid_credentials

During the incident: Contacted law enforcement
Engaged leading cybersecurity firms to assist in assessing the incident’s scope and cause
Offering credit monitoring/identity protection services through Kroll
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 28 weeks(199 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 4 filings · 4 states

View merged incident ↗

Vermont State AGJul 1 · first

Montana State AGJul 1 · first · this page

Massachusetts State AG+1d

New Hampshire State AG+7d

Pattern: first filing Jul 1 (VT), last Jul 8 (NH) — a 7-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://dojmt.gov/wp-content/uploads/OCP/Consumer-notification-letter-1520.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jul 1, 2024
Raw hash: 87b24906373aec556b733022072162a91bc9dc7c227893531bca9627bb38bd07

Linked disclosures

Regulatory filings (3) · sorted by filing gap

Reporting entityCornerstone Healthcare Group Management Services LLC

Victim entityCornerstone Healthcare Group Management Services LLC

Incidentdiscovered Dec 15, 2023

Stated responseContacted law enforcement

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov