HackingGovernmentGovernmentData ExfiltratedCustomer Data InvolvedAuthenticationEducationFinancial accountHealth (basic)Identity (basic)Government IDPHICriticalContained

Chelan County, WA

bd_167c047191135e4a · schema v1 · pii pii-v1

Severity

Critical

Discovered

May 24, 2026

Filed

Aug 11, 2026

To disclose

11 weeks

Affected

500,001state residents only

Confidence

66%

Full breach record for Chelan County, WA →

Chelan County, WA notified the Washington Attorney General of a data breach affecting at least 500,001 residents. Unauthorized access occurred between May 20 and May 24, 2026. Exposed data included names, SSNs, driver's license numbers, financial account info, DOB, passport numbers, and medical information. Notification to residents was sent on August 11, 2026, via website and media. Federal law enforcement was notified.

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Washington clock⏱ WA AG >30d11 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 4 days

discovery → filing · 11 weeks / 79 days

May 20, 2026

Begins

May 24, 2026

Discovered

Aug 11, 2026

Filed

vs. sector median

on median

Tracked as a single-filing incident — the only disclosure on record for this event so far.Confirmed500,001 affectedView incident

Name: Chelan County, WA
norm: chelan county wa

Name: Chelan County, WA
norm: chelan county wa
Industry: Governmentllm

Discovered: May 24, 2026
Breach occurred: May 20, 2026 – May 24, 2026
Undetected for: 4 daysoccurrence → discovery
Materiality determined: —
Notification sent: Aug 11, 2026
Affected individuals: 500,001state-resident count only
Data types: AuthenticationEducationFinancial accountHealth (basic)Identity (basic)Government IDPHI
Attack vector: Unauthorized Access
MITRE ATT&CK: T1119 Automated Collection
Threat actor: External

During the incident: Notified federal law enforcement early in the investigation
Provided notice to Washington residents via a posting on its website and notice to statewide media
Provided impacted individuals with guidance on how to better protect against identity theft and fraud
Provided individuals with information on how to place a fraud alert and security freeze on one’s credit file
Provided contact details for the national consumer reporting agencies
Provided information on how to obtain a free credit report
Changes made: Reviewing its existing policies and procedures to reduce the likelihood of similar future events
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 11 weeks(79 days from discovery to filing)
Compliance flags: WA AG >30d
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

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/BreachA42288.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Aug 11, 2026
Raw hash: e1161beaa73d4be387d60b0f222ca5ca949a914f5f4a2da5480ee9b7d621c7e5

Reporting entityChelan County, WA

Victim entityChelan County, WA

Incidentdiscovered May 24, 2026

Stated responseNotified federal law enforcement early in the investigation

ComplianceWA AG >30d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com