HackingHealthcareFinancial ServicesHealthcareVulnerability ExploitZero-DayData ExfiltratedCustomer Data InvolvedIdentity (basic)Government IDFinancial accountPHIHealth (basic)CriticalContained

DELTA DENTAL OF CALIFORNIA

bd_9c3c9a75bc9bb912 · schema v1 · pii pii-v1

Severity

Critical

Discovered

Jun 1, 2023

Filed

Dec 14, 2023

To disclose

28 weeks

Affected

106,098state residents only

Linked

11 filings

Confidence

70%

Full breach record for DELTA DENTAL OF CALIFORNIA →5 incidents on file

Delta Dental of California and affiliates reported a supplemental breach affecting 106,098 Washington residents. Unauthorized actors exploited a zero-day vulnerability in MOVEit Transfer software between May 27-30, 2023. The incident was discovered on June 1, 2023. Affected data included names, SSNs, driver's licenses, financial accounts, and health information. Notifications were sent in December 2023.

J jump to incidentP pin to compareR raw source

Washington clock✗ WA AG >90d28 weeks 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 · 5 days

discovery → filing · 28 weeks / 196 days

May 27, 2023

Begins

Jun 1, 2023

Discovered

Dec 14, 2023

Filed

vs. sector median

+15 wks slower

This filing is one of 11 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Massachusetts State AGbd_2aecb331d440f93c2023-12-14Verified
Oregon State AGbd_2c29103cacdbca1f2023-12-14Candidate
Vermont State AGbd_40e8f6904a6f52b92023-12-14Verified
Montana State AGbd_54f04c0719e262cf2023-12-14Verified

Show 6 more filings ↓up to 95d gap

Maine State AGbd_b0392e182589e9502023-12-29 · +15dVerified by operator
Washington State AGbd_2b669447999006a92024-01-30 · +47dVerified
Montana State AGbd_999bf44f190153fb2024-02-07 · +55dVerified
Washington State AGbd_f32bc4138c99af892024-02-07 · +55dVerified
New Hampshire State AGbd_b33482b171701d942024-03-15 · +92dVerified
Hawaii State AGbd_48ccff9e491e5a462024-03-18 · +95dVerified

Name: SHEPPARD, MULLIN, RICHTER & HAMPTON LLP
norm: sheppard mullin richter hampton

Name: DELTA DENTAL OF CALIFORNIA
norm: delta dental of california
Domain: deltadentalca.com
Industry: HealthcarellmFinancial Servicesllm

Discovered: Jun 1, 2023
Breach occurred: May 27, 2023 – May 30, 2023
Undetected for: 5 daysoccurrence → discovery
Materiality determined: —
Notification sent: Dec 14, 2023
Affected individuals: 106,098state-resident count only
Data types: Identity (basic)Government IDFinancial accountPHIHealth (basic)
Data elements: NameSocial Security numberDriver's licence numberFinancial account numberDate of birthPassport numberHealth insurance IDMedical information
WA-stated cause: Unauthorized Access
WA-stated duration: lifecycle 1-99dexposure 1-99d
WA-stated discovery: Found after the fact
Attack vector: Unauthorized Access
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1041 Exfiltration Over C2 Channel
Threat actor: ExternalFinancial
Regulator citations: Notified Washington Office of the Attorney General
Initial access: exploit_public_facing

During the incident: Stopped access to the MOVEit software
Removed the malicious files
Conducted a thorough analysis of the MOVEit database
Applied the recommended patches from Progress Software Corporation
Reset administrative passwords to the MOVEit system
Enhanced unauthorized access monitoring related to the MOVEit Transfer file access, malicious activity, and ransomware activity
Engaged independent third-party experts in computer forensics, analytics, and data mining
Notified law enforcement
Offered twenty-four months of credit monitoring and identity protection services through Kroll
Changes made: Applied the recommended patches from Progress Software Corporation
Reset administrative passwords to the MOVEit system
Enhanced unauthorized access monitoring related to the MOVEit Transfer file access, malicious activity, and ransomware activity
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 28 weeks(196 days from discovery to filing)
Compliance flags: WA AG >90d
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.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 8 states

View merged incident ↗

Massachusetts State AGDec 14 · first

Oregon State AGDec 14 · first

Vermont State AGDec 14 · first

Montana State AGDec 14 · first

Washington State AGDec 14 · first · this page

Maine State AG+15d

Washington State AG+47d

Montana State AG+55d

Washington State AG+55d

New Hampshire State AG+92d

Hawaii State AG+95d

Pattern: first filing Dec 14 (MA), last Mar 18 (HI) — a 95-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://agportal-s3bucket.s3.amazonaws.com/databreach/BreachA27266.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Dec 14, 2023
Raw hash: 983ed832a682d93316a08c56b34cec8ff8472394fc8b2c97ad4f005a76dfe1ed

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entitySHEPPARD, MULLIN, RICHTER & HAMPTON LLP

Victim entityDELTA DENTAL OF CALIFORNIA

Incidentdiscovered Jun 1, 2023

Stated responseStopped access to the MOVEit software

ComplianceWA AG >90d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com