HackingHealthcareHealthcareData ExfiltratedCustomer Data InvolvedPHIHealth (basic)Identity (basic)LowContained

Prospect Medical Holdings, Inc.

bd_e78b914f634463f7 · schema v1 · pii pii-v1

Severity

Low

Discovered

Aug 1, 2023

Filed

Dec 13, 2023

To disclose

19 weeks

Affected

Not disclosed

Linked

13 filings

Confidence

64%

Full breach record for Prospect Medical Holdings, Inc. →

Prospect Medical Holdings, Inc. notified individuals of a data security incident where unauthorized parties accessed its IT environment between July 31 and August 3, 2023. The activity was first identified on August 1, 2023. Systems were taken offline immediately. Files containing protected health information (PHI) and personal information were accessed or acquired. A third-party forensics firm assisted in the investigation.

J jump to incidentP pin to compareR raw source

Leak gap clock⏱ Leak >90d19 weeks discovery → filing

Incident timeline

undetected · 1 days

discovery → filing · 19 weeks / 134 days

Jul 31, 2023

Begins

Aug 1, 2023

Discovered

Dec 13, 2023

Filed

vs. sector median

+8 wks slower

This filing is one of 13 about the same incident.View merged incident

A leak claim by rhysida about this victim predates this filing by 111 days.View originating leak claim

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Indiana State AGbd_01179efaed3e75352023-09-29 · +75dVerified
HHS OCRbd_2fef4c679272ccd32023-09-29 · +75dVerified
New Hampshire State AGbd_35efeda2e5a8d88f2023-09-29 · +75dVerified
Maine State AGbd_6ef44d457fd8b2602023-09-29 · +75dVerified

Show 6 more filings ↓up to 79d gap

Vermont State AGbd_91573382e8c024192023-09-29 · +75dVerified
California State AGbd_bd24866d0fea52f92023-09-29 · +75dVerified
Massachusetts State AGbd_c20d4bad3ff6d87f2023-09-29 · +75dVerified
Montana State AGbd_f1bc0b4d5ad05a502023-09-29 · +75dVerified
New Hampshire State AGbd_610b4d3b2e537df72024-02-29 · +78dVerified
Massachusetts State AGbd_e9100cb92bc339de2024-03-01 · +79dVerified

Showing first 10 of 12 linked disclosures.

Name: Prospect Medical Holdings, Inc.
norm: prospect medical
Domain: pmh.com

Name: Prospect Medical Holdings, Inc.
norm: prospect medical
Domain: pmh.com
Industry: Healthcarellm

Discovered: Aug 1, 2023
Breach occurred: Jul 31, 2023 – Aug 3, 2023
Undetected for: 1 dayoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: Not disclosed
Data types: PHIHealth (basic)Identity (basic)
Attack vector: Unknown
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External

During the incident: Took all systems, including servers and workstations, offline
Launched an investigation with the assistance of a third-party forensics firm
Implemented and will continue to adopt additional safeguards and technical security measures
Changes made: Implemented and will continue to adopt additional safeguards and technical security measures to further protect and monitor our systems
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 19 weeks(134 days from discovery to filing)
Compliance flags: Leak >90d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 7 states

View merged incident ↗

Indiana State AGSep 29 · first

HHS OCRSep 29 · first

New Hampshire State AGSep 29 · first

Maine State AGSep 29 · first

Vermont State AGSep 29 · first

California State AGSep 29 · first

Massachusetts State AGSep 29 · first

Montana State AGSep 29 · first

California State AG+75d · this page

New Hampshire State AG+153d

Massachusetts State AG+154d

Pattern: first filing Sep 29 (IN), last Mar 1 (MA) — a 154-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Cascade drawn from the first 10 linked disclosures of 12 — the full spread may be wider.

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://oag.ca.gov/ecrime/databreach/reports/sb24-577827
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Dec 13, 2023
Raw hash: 710f76a1023b46cbb7866033cd5bfb26accf8b736401eda723c4b32abbe6a04e

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityProspect Medical Holdings, Inc.

Victim entityProspect Medical Holdings, Inc.

Incidentdiscovered Aug 1, 2023

Stated responseTook all systems, including servers and workstations, offline

ComplianceLeak >90d

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov