HackingHealthcareProfessional ServicesHealthcareSupply Chain (3P Vendor)Customer Data InvolvedBusiness Associate (HIPAA)PHIIdentity (basic)Health (basic)LowContained

Community Memorial Health System

bd_ea74e56b7df0e770 · schema v1 · pii pii-v1

Severity

Low

Discovered

Mar 31, 2021

Filed

Jul 16, 2021

To disclose

15 weeks

Affected

Not disclosed

Confidence

65%

Full breach record for Community Memorial Health System →6 incidents on file

Guidehouse, a professional services provider, notified the California Attorney General of a cyber attack occurring in late January 2021. The attack compromised a third-party secure file transfer service used by Guidehouse, affecting data for clients including Community Memorial Health System in Ventura, CA. Guidehouse discovered the incident in late March 2021. Affected data may include names, dates of birth, member IDs, addresses, and certain medical information. Guidehouse ceased using the compromised service, engaged cybersecurity experts, and cooperated with federal law enforcement. Affected individuals were offered two years of credit monitoring.

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Incident timeline

undetected · 70 days

discovery → filing · 15 weeks / 107 days

Jan 20, 2021

Begins

Mar 31, 2021

Discovered

Jul 16, 2021

Filed

vs. sector median

+3 wks slower

Tracked as a single-filing incident — the only disclosure on record for this event so far.ConfirmedView incident

Name: GUIDEHOUSE INC.
norm: guidehouse

Name: Community Memorial Health System
norm: community memorial health system
Industry: HealthcarellmProfessional Servicesllm

Discovered: Mar 31, 2021
Breach occurred: Jan 20, 2021
Undetected for: 70 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jul 16, 2021
Affected individuals: Not disclosed
Data types: PHIIdentity (basic)Health (basic)
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1195 Supply Chain Compromise
Threat actor: External
Regulator citations: Cooperated with federal law enforcement
Third party: via Third-party service used for secure file transfer
Initial access: supply_chain

During the incident: Immediately launched an investigation
Ceased using the third-party service that had been compromised
Cooperated with federal law enforcement
Engaged leading cyber security experts in connection with investigating and responding to the incident
Notified Community Memorial Health System on May 21, 2021
Arranged for complimentary, two-year credit monitoring service through Experian IdentityWorks
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 15 weeks(107 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

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/sb24-542968
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jul 16, 2021
Raw hash: 3ef36c64ce8fbce81bed90dde50db68ddac28a200b524c07857017f8cf171301

Reporting entityGUIDEHOUSE INC.

Victim entityCommunity Memorial Health System

Incidentdiscovered Mar 31, 2021

Stated responseImmediately launched an investigation

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov