HackingHealthcareHealthcareData ExfiltratedCustomer Data InvolvedGovernment IDIdentity (basic)CriticalContained

Prospect Medical Holdings, Inc.

bd_6ef44d457fd8b260 · schema v1 · pii pii-v1

Severity

Critical

Discovered

Sep 13, 2023

Filed

Sep 29, 2023

To disclose

16 days

Affected · nationwide

190,49267 in this filing

Linked

13 filings

Confidence

65%

Full breach record for Prospect Medical Holdings, Inc. →

Prospect Medical Holdings, Inc. reported an external system breach (hacking) occurring between July 31, 2023, and August 3, 2023, discovered on September 13, 2023. The incident affected 190,492 individuals nationwide, including 67 Maine residents. Acquired data included names and Social Security Numbers. The company provided written notification and offered one year of credit monitoring and identity theft protection services through IDX.

J jump to incidentP pin to compareR raw source

Leak gap clock⏱ Leak >30d16 days discovery → filing

⚠ AG web formThe discovery date came from the AG web-form field, which is systematically later than the detection date stated in the letter. Treat the clock as indicative.

Incident timeline

undetected · 44 days

discovery → filing · 16 days

Jul 31, 2023

Begins

Sep 13, 2023

Discovered

Sep 29, 2023

Filed

vs. sector median

9 wks faster

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 36 days.View originating leak claim

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Indiana State AGbd_01179efaed3e75352023-09-29Verified
HHS OCRbd_2fef4c679272ccd32023-09-29Verified
New Hampshire State AGbd_35efeda2e5a8d88f2023-09-29Verified
Vermont State AGbd_91573382e8c024192023-09-29Verified

Show 6 more filings ↓up to 154d gap

California State AGbd_bd24866d0fea52f92023-09-29Verified
Massachusetts State AGbd_c20d4bad3ff6d87f2023-09-29Verified
Montana State AGbd_f1bc0b4d5ad05a502023-09-29Verified
California State AGbd_e78b914f634463f72023-12-13 · +75dVerified
New Hampshire State AGbd_610b4d3b2e537df72024-02-29 · +153dVerified
Massachusetts State AGbd_e9100cb92bc339de2024-03-01 · +154dVerified

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: Sep 13, 2023
Breach occurred: Jul 31, 2023 – Aug 3, 2023
Undetected for: 44 daysoccurrence → discovery
Materiality determined: —
Notification sent: Sep 29, 2023
Affected individuals: 190,492state + nationwide
Data types: Government IDIdentity (basic)
Data elements: Social Security number
Attack vector: Unauthorized Access
MITRE ATT&CK: T1190 Exploit Public-Facing Application
Threat actor: External
Initial access: exploit_public_facing

During the incident: Sent written notification to affected individuals
Offered one year of credit monitoring and identity theft protection services through IDX
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 16 days(16 days from discovery to filing)
Compliance flags: Leak >30dME AG ≤30d · 16d
Discovery-date grounding: AG web formThe discovery date came from the AG web-form field, which is systematically later than the detection date stated in the letter. Treat the clock as indicative.
Clock breakdown: Statute Window Elapsed Threshold Status
Maine
Discovered: Sep 13, 2023
→ Filed with AG: Sep 29, 2023
16d 30 days ME AG ≤30d

Statute	Window	Elapsed	Threshold	Status
Maine	Discovered: Sep 13, 2023 → Filed with AG: Sep 29, 2023	16d	30 days	ME AG ≤30d

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

Vermont State AGSep 29 · first

California State AGSep 29 · first

Massachusetts State AGSep 29 · first

Montana State AGSep 29 · first

Maine State AGSep 29 · first · this page

California State AG+75d

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://www.maine.gov/agviewer/content/ag/985235c7-cb95-4be2-8792-a1252b4f8318/c4f1f925-6136-45dd-99fa-6c92cab12031.shtml
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Sep 29, 2023
Raw hash: 4ed5f65f79472a2ffcf1088b60cd1bd7e4beeb782ce05d2b2bbeda223a84156d

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityProspect Medical Holdings, Inc.

Victim entityProspect Medical Holdings, Inc.

Incidentdiscovered Sep 13, 2023

Stated responseSent written notification to affected individuals

ComplianceLeak >30d

Extraction provenanceno artifact recorded

Source provenancewww.maine.gov