HackingHealthcareTechnologyHealthcareVulnerability ExploitCapture Stored DataData ExfiltratedTargetedMulti-Stage ChainIdentity (basic)Government IDHealth (basic)PHIMediumContained

Highmark Blue Cross Blue Shield

bd_e7c0d33d4e677b2c · schema v1 · pii pii-v1

Severity

Medium

Discovered

Jul 26, 2023

Filed

Jan 8, 2024

To disclose

24 weeks

Affected

504state residents only

Confidence

68%

Full breach record for Highmark Blue Cross Blue Shield →

Welltok, Inc. reported a supplemental data event on behalf of Highmark Blue Cross Blue Shield. An unknown actor exploited vulnerabilities in Welltok's MOVEit Transfer server on May 30, 2023, exfiltrating PHI and PII. Welltok was alerted on July 26, 2023. Notices were sent to 504 Washington residents starting January 5, 2024.

J jump to incidentP pin to compareR raw source

Washington clock⏱ WA AG >30d24 weeks discovery → filing

Incident timeline

undetected · 57 days

discovery → filing · 24 weeks / 166 days

May 30, 2023

Begins

Jul 26, 2023

Discovered

Jan 8, 2024

Filed

vs. sector median

+11 wks slower

Tracked as a single-filing incident — the only disclosure on record for this event so far.Confirmed504 affectedView incident

Name: Welltok, Inc.
norm: welltok

Name: Highmark Blue Cross Blue Shield
norm: highmark blue cross blue shield
Industry: HealthcarellmTechnologyllm

Discovered: Jul 26, 2023
Breach occurred: May 30, 2023
Undetected for: 57 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jan 5, 2024
Affected individuals: 504state-resident count only
Data types: Identity (basic)Government IDHealth (basic)PHI
Data elements: NameDate of birthHealth insurance IDMedical information
WA-stated cause: Cyberattack
WA-stated duration: lifecycle Unknowndexposure Unknownd
WA-stated discovery: Found after the fact
Attack vector: Misconfiguration
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1041 Exfiltration Over C2 Channel
Threat actor: ExternalFinancial
Regulator citations: Supplemental Notice of Data Event filed with Washington State Office of the Attorney General
Initial access: exploit_public_facing

During the incident: Launched an additional investigation with the assistance of third-party cybersecurity specialists
Providing access to credit monitoring services for twelve (12) to twenty-four (24) months... through Experian
Providing impacted individuals with guidance on how to better protect against identity theft and fraud
Changes made: Reviewing and enhancing its existing policies and procedures related to data privacy
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 24 weeks(166 days from discovery to filing)
Compliance flags: WA AG >30d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.

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://agportal-s3bucket.s3.amazonaws.com/databreach/BreachM16394.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jan 8, 2024
Raw hash: 65b53f7dd8fd431852e7e17bdde0ae09156cbd82650db6157355f7ebbd6759ff

Reporting entityWelltok, Inc.

Victim entityHighmark Blue Cross Blue Shield

Incidentdiscovered Jul 26, 2023

Stated responseLaunched an additional investigation with the assistance of third-party cybersecurity specialists

ComplianceWA AG >30d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com