HackingFinancial ServicesFinanceStolen CredentialsCustomer Data InvolvedIdentity (basic)Government IDFinancial accountMediumContained

West Plains Bank and Trust Company

bd_e21baa142e215257 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Nov 18, 2021

Filed

Mar 10, 2022

To disclose

16 weeks

Affected

5state residents only

Linked

5 filings

Confidence

65%

Full breach record for West Plains Bank and Trust Company →

West Plains Bank and Trust Company notified the Montana AG of unauthorized access to an employee email account from Aug 14 to Sep 7, 2021. The incident affected 5 Montana residents, exposing names, SSNs, and financial account details. The bank engaged forensic specialists, reset credentials, and provided 12 months of credit monitoring.

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Incident timeline

undetected · 96 days

discovery → filing · 16 weeks / 112 days

Aug 14, 2021

Begins

Nov 18, 2021

Discovered

Mar 10, 2022

Filed

vs. sector median

+8 wks slower

This filing is one of 5 filings about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (4) · sorted by filing gap

New Hampshire State AGbd_fb47569767581d5e2022-01-18 · +51dVerified
Indiana State AGbd_200287936abec7be2022-01-12 · +57dVerified
Maine State AGbd_6b5bda52c338bb0f2022-01-12 · +57dCandidate
Massachusetts State AGbd_75458e6f4c4dccaa2022-01-12 · +57dVerified

Name: Mullen Coughlin LLC
norm: mullen coughlin

Name: West Plains Bank and Trust Company
norm: west plains bank and
Domain: westplainsbank.com
Industry: Financial Servicesllm

Discovered: Nov 18, 2021
Breach occurred: Aug 14, 2021 – Sep 7, 2021
Undetected for: 96 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jan 12, 2022
Affected individuals: 5state-resident count only
Data types: Identity (basic)Government IDFinancial account
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Regulator citations: Notified Montana Department of Justice Office of Consumer Protection
Initial access: valid_credentials

During the incident: Launched an investigation, with the assistance of third-party forensic specialists
Reviewed the contents of the affected account
Provided written notice of this incident to all affected individuals
Working to implement additional safeguards and training to its employees
Providing access to credit monitoring services for one (1) year, through Experian to individuals whose personal information was potentially affected by this incident, at no cost to these individuals
Changes made: Implementing additional safeguards and training to its employees
Changing the password for the affected account
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 16 weeks(112 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 5 filings · 5 states

View merged incident ↗

Indiana State AGJan 12 · first

Maine State AGJan 12 · first

Massachusetts State AGJan 12 · first

New Hampshire State AG+6d

Montana State AG+57d · this page

Pattern: first filing Jan 12 (IN), last Mar 10 (MT) — a 57-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://dojmt.gov/wp-content/uploads/OCP/Consumer-Notification-Letter-256.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Mar 10, 2022
Raw hash: f122699dc975488d002adfafb8303fecd8663e17100be361a89ec81f9656f7f1

Linked disclosures

Regulatory filings (4) · sorted by filing gap

Reporting entityMullen Coughlin LLC

Victim entityWest Plains Bank and Trust Company

Incidentdiscovered Nov 18, 2021

Stated responseLaunched an investigation, with the assistance of third-party forensic specialists

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov