HackingHealthcareHealthcareEmployee Data InvolvedCustomer Data InvolvedIdentity (basic)Government IDPHIMediumContained

Prospect Medical Holdings, Inc.

bd_bd24866d0fea52f9 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Aug 1, 2023

Filed

Sep 29, 2023

To disclose

8 weeks

Affected

Not disclosed

Linked

13 filings

Confidence

65%

Full breach record for Prospect Medical Holdings, Inc. →

Prospect Medical Holdings, Inc. notified California residents of a data breach where an unauthorized party accessed IT network files between July 31 and August 3, 2023. The company discovered the incident on August 1, 2023. Affected data included names and Social Security numbers of employees, dependents, and patients. The company engaged forensic investigators, notified law enforcement, and offered one year of credit monitoring and identity protection services.

J jump to incidentP pin to compareR raw source

California clockDiscovered Aug 1, 2023 → Notified Sep 29, 202359d ✓ CA 60-day OK8 weeks discovery → filing

Incident timeline

undetected · 1 days

discovery → filing · 8 weeks / 59 days

Jul 31, 2023

Begins

Aug 1, 2023

Discovered

Sep 29, 2023

Filed

vs. sector median

3 wks faster

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

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
Maine State AGbd_6ef44d457fd8b2602023-09-29Verified

Show 6 more filings ↓up to 154d gap

Vermont State AGbd_91573382e8c024192023-09-29Verified
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: Aug 1, 2023
Breach occurred: Jul 31, 2023 – Aug 3, 2023
Undetected for: 1 dayoccurrence → discovery
Materiality determined: —
Notification sent: Sep 29, 2023
Affected individuals: Not disclosed
Data types: Identity (basic)Government IDPHI
Data elements: Social Security number
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External

During the incident: Took steps to secure our systems
Contained the incident
Notified law enforcement
Engaged the expertise of a third-party forensic investigation firm to conduct a thorough investigation
Changes made: Implemented additional safeguards and technical security measures to further protect and monitor our systems
Arranged for credit monitoring and identity protection services through the company IDX at no cost
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 8 weeks(59 days from discovery to filing)
Compliance flags: CA 60-day OK · 59d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.
Clock breakdown: Statute Window Elapsed Threshold Status
California
Discovered: Aug 1, 2023
→ Notified: Sep 29, 2023
59d 60 days (analyst band, pre-2026 discoveries) CA 60-day OK

Statute	Window	Elapsed	Threshold	Status
California	Discovered: Aug 1, 2023 → Notified: Sep 29, 2023	59d	60 days (analyst band, pre-2026 discoveries)	CA 60-day OK

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

Massachusetts State AGSep 29 · first

Montana State AGSep 29 · first

California 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://oag.ca.gov/ecrime/databreach/reports/sb24-574490
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: d878277bcedf1d8f7607be1f325827571a76fdd6b59f75f3f0a1360648362aa7

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 steps to secure our systems

ComplianceCA 60-day OK

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov