HackingHealthcareHealthcareSupply Chain (3P Vendor)Customer Data InvolvedData ExfiltratedPHIHealth (basic)Identity (basic)LowContained

Catalyst Physician Group

bd_8925f3925d1e5282 · schema v1 · pii pii-v2

Severity

Low

Discovered

Dec 18, 2025

Filed

Sep 11, 2026

To disclose

38 weeks

Affected

Not disclosed

Linked

3 filings

Confidence

69%

Full breach record for Catalyst Physician Group →

Catalyst Physician Group notified patients of a data breach involving protected health information (PHI) stored by third-party vendor Aesto, LLC. An unauthorized actor accessed data between December 2 and December 18, 2025. Aesto discovered the incident on December 18, 2025. Affected data includes full names and other PHI. The company engaged forensic investigators and is offering identity theft protection services.

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California clockDiscovered Dec 18, 2025 → Notified Sep 11, 2026267d ✗ CA 60-day late38 weeks discovery → filing

Incident timeline

undetected · 16 days

discovery → filing · 38 weeks / 267 days

Dec 2, 2025

Begins

Dec 18, 2025

Discovered

Sep 11, 2026

Filed

vs. sector median

+27 wks slower

This filing is one of 3 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (2) · sorted by filing gap

Texas State AGbd_b9a49e9684fcffbf2026-09-15 · +4dVerified
Massachusetts State AGbd_f402870fea4371242026-09-01 · +10dCandidate

Name: Catalyst Physician Group
norm: catalyst physician

Name: Catalyst Physician Group
norm: catalyst physician
Industry: Healthcarellm

Discovered: Dec 18, 2025
Breach occurred: Dec 2, 2025 – Dec 18, 2025
Undetected for: 16 daysoccurrence → discovery
Materiality determined: —
Notification sent: Sep 11, 2026
Affected individuals: Not disclosed
Data types: PHIHealth (basic)Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Regulator citations: Filed breach notification with California Attorney General
Third party: via Aesto, LLC

During the incident: Commenced a prompt and thorough investigation
Worked closely with external cybersecurity professionals experienced in handling these types of incidents
Conducted extensive forensic investigation and manual document review
Offering a complimentary 12/24 month membership of identity theft protection services through IDX
Set up a dedicated and confidential toll-free response line to respond to questions
Changes made: Continually evaluate and modify practices and internal controls to enhance the security and privacy of personal information
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 38 weeks(267 days from discovery to filing)
Compliance flags: CA 60-day late · 267d
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: Dec 18, 2025
→ Notified: Sep 11, 2026
267d 60 days (analyst band, pre-2026 discoveries) CA 60-day late

Statute	Window	Elapsed	Threshold	Status
California	Discovered: Dec 18, 2025 → Notified: Sep 11, 2026	267d	60 days (analyst band, pre-2026 discoveries)	CA 60-day late

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 3 filings · 3 states

View merged incident ↗

Massachusetts State AGSep 1 · first

California State AG+10d · this page

Texas State AG+14d

Pattern: first filing Sep 1 (MA), last Sep 15 (TX) — a 14-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://oag.ca.gov/ecrime/databreach/reports/sb24-629605
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Sep 11, 2026
Raw hash: 14ed96738053b5102b2ddbb1bb99434b8e2a6fd4492910d2749c89b29733777c

Linked disclosures

Regulatory filings (2) · sorted by filing gap

Reporting entityCatalyst Physician Group

Victim entityCatalyst Physician Group

Incidentdiscovered Dec 18, 2025

Stated responseCommenced a prompt and thorough investigation

ComplianceCA 60-day late

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov