HackingHealthcareFinancial ServicesHealthcareVulnerability ExploitCapture Stored DataSupply Chain (3P Vendor)Data ExfiltratedTargetedIdentity (basic)Government IDPHIHealth (basic)HighContained

Blue Shield of California (BSC)

bd_16731eb00b06f372 · schema v1 · pii pii-v1

Severity

High

Discovered

Aug 23, 2023

Filed

Nov 17, 2023

To disclose

12 weeks

Affected

2,962state residents only

Linked

2 filings

Confidence

69%

Full breach record for Blue Shield of California (BSC) →4 incidents on file

Blue Shield of California, a health insurer, notified affected individuals of a data breach involving its contracted vision benefits vendor. The vendor's MOVEit server was compromised via an unknown vulnerability, leading to data exfiltration between May 28-31, 2023. Blue Shield discovered the incident on August 23, 2023. Affected data included names and government IDs. 2,962 Washington residents were notified.

J jump to incidentP pin to compareR raw source

Washington clock⏱ WA AG >30d12 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 · 87 days

discovery → filing · 12 weeks / 86 days

May 28, 2023

Begins

Aug 23, 2023

Discovered

Nov 17, 2023

Filed

vs. sector median

on median

This filing is one of 2 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (1) · sorted by filing gap

Montana State AGbd_2b808583c3d2e06b2023-11-17Verified

Name: Medical Eye Services, Inc. (Blue Shield of California)
norm: medical eye services blue shield of california

Name: Blue Shield of California (BSC)
norm: blue shield of california bsc
Industry: HealthcarellmFinancial Servicesllm

Discovered: Aug 23, 2023
Breach occurred: May 28, 2023 – May 31, 2023
Undetected for: 87 daysoccurrence → discovery
Materiality determined: —
Notification sent: Sep 1, 2023
Affected individuals: 2,962state-resident count only
Data types: Identity (basic)Government ID
Data elements: NameSocial Security numberDate of birthMedical information
WA-stated cause: Unauthorized Access
WA-stated duration: lifecycle 1-99dexposure 1-99d
WA-stated discovery: Found after the fact
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1041 Exfiltration Over C2 ChannelT1195 Supply Chain Compromise
Threat actor: ExternalFinancial
Regulator citations: reported the matter to the FBI
Initial access: exploit_public_facing

During the incident: Took the server offline
Launched an investigation into the incident
Engaged a cybersecurity firm
Reported the matter to the FBI
Offering complimentary credit monitoring and identity restoration services through Kroll
Changes made: Rebuilt the MOVEit system in accordance with gold standard build requirements
Undertook a number of technical measures to validate security controls put in place
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 12 weeks(86 days from discovery to filing)
Compliance flags: WA AG >30d
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 · 2 filings · 2 states

View merged incident ↗

Montana State AGNov 17 · first

Washington State AGNov 17 · first · this page

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/BreachA27052.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Nov 17, 2023
Raw hash: 5292da6dc7962335d1f46beffe063d300a491877208f4ca384c196a4de4f6115

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entityMedical Eye Services, Inc. (Blue Shield of California)

Victim entityBlue Shield of California (BSC)

Incidentdiscovered Aug 23, 2023

Stated responseTook the server offline

ComplianceWA AG >30d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com