HackingFinancial ServicesFinanceStolen CredentialsTargetedData ExfiltratedAuthenticationFinancial accountIdentity (basic)Government IDHighContained

Columbia Bank

bd_c71b2e03d88edcf3 · schema v1 · pii pii-v1

Severity

High

Discovered

Dec 19, 2025

Filed

Apr 17, 2026

To disclose

17 weeks

Affected

1,607state residents only

Linked

4 filings

Confidence

70%

Full breach record for Columbia Bank →2 incidents on file

Columbia Bank notified Washington AG of a data breach affecting 1,607 residents. Unauthorized access occurred Oct 2–Dec 22, 2025, involving personal info (names, SSNs, driver’s licenses, financial accounts). Discovered Dec 19, 2025. Response included forensic investigation, law enforcement notification, and credit monitoring services.

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Washington clock✗ WA AG >90d17 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 · 78 days

discovery → filing · 17 weeks / 119 days

Oct 2, 2025

Begins

Dec 19, 2025

Discovered

Apr 17, 2026

Filed

vs. sector median

+9 wks slower

This filing is one of 4 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (3) · sorted by filing gap

Oregon State AGbd_2459fe2d347c53ee2026-04-17Verified
Nebraska State AGbd_6763df597a598e952026-04-17Verified
California State AGbd_cbff3120c1de99f82026-04-17Verified

Name: Columbia Bank
norm: columbia bank

Name: Columbia Bank
norm: columbia bank
Industry: Financial Servicesllm

Discovered: Dec 19, 2025
Breach occurred: Oct 2, 2025 – Dec 22, 2025
Undetected for: 78 daysoccurrence → discovery
Materiality determined: —
Notification sent: Apr 17, 2026
Affected individuals: 1,607state-resident count only
Data types: Identity (basic)Government IDFinancial account
Data elements: NameSocial Security numberDriver's licence numberFinancial account numberDate of birthUsername + password
WA-stated cause: Theft or Mistake
WA-stated duration: lifecycle 1-99dexposure 1-99d
WA-stated discovery: Found while ongoing
Attack vector: Unauthorized Access
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1078 Valid Accounts
Threat actor: ExternalFinancial
Regulator citations: Notified Washington Attorney General
Initial access: valid_credentials

During the incident: Began an internal investigation
Worked to secure our systems
Notified law enforcement
Engaged a forensic security firm to assist with our investigation
Changes made: Enhancing our technical security measures
Arranged for you to enroll in a one-year membership of Experian IdentityWorksSM Credit 3B
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 17 weeks(119 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 · 4 filings · 4 states

View merged incident ↗

Oregon State AGApr 17 · first

Nebraska State AGApr 17 · first

California State AGApr 17 · first

Washington State AGApr 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/BreachA37811.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 17, 2026
Raw hash: 6b55c52fca5c1a303d37981ada81638a81e1f39df4770017844facbf9169e4d0

Linked disclosures

Regulatory filings (3) · sorted by filing gap

Reporting entityColumbia Bank

Victim entityColumbia Bank

Incidentdiscovered Dec 19, 2025

Stated responseBegan an internal investigation

ComplianceWA AG >90d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com