HackingManufacturingManufacturingStolen CredentialsTargetedIdentity (basic)LowContained

Hamilton Construction Company

bd_4e6c6d46de10a078 · schema v1 · pii pii-v1

Severity

Low

Discovered

Jun 19, 2025

Filed

Nov 12, 2025

To disclose

21 weeks

Affected

21state residents only

Linked

4 filings

Confidence

65%

Full breach record for Hamilton Construction Company →

Hamilton Construction Company notified Montana residents of unauthorized network access on June 19, 2025. The incident involved access to files containing names and potentially other PII. The company secured the network, investigated, and offered credit monitoring services to affected individuals.

J jump to incidentP pin to compareR raw source

Incident timeline

discovery → filing · 21 weeks / 146 days

Jun 19, 2025

Begins

Jun 19, 2025

Discovered

Nov 12, 2025

Filed

vs. sector median

+10 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

Nebraska State AGbd_3891a4fb15ceb59d2025-11-12Verified
Washington State AGbd_702357320a487dee2025-11-12Verified
Oregon State AGbd_37032daff42f3bab2025-12-15 · +33dVerified

Name: Hamilton Construction Company
norm: hamilton construction

Name: Hamilton Construction Company
norm: hamilton construction
Industry: Manufacturingllm

Discovered: Jun 19, 2025
Breach occurred: Jun 19, 2025
Undetected for: 0 daysoccurrence → discovery
Materiality determined: —
Notification sent: Oct 7, 2025
Affected individuals: 21state-resident count only
Data types: Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Initial access: valid_credentials

During the incident: Took steps to secure the network
Assess the security of our systems
Investigate the activity
Offering you access to credit monitoring services
Changes made: Reviewing and enhancing our existing policies and procedures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 21 weeks(146 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 4 filings · 4 states

View merged incident ↗

Nebraska State AGNov 12 · first

Washington State AGNov 12 · first

Montana State AGNov 12 · first · this page

Oregon State AG+33d

Pattern: first filing Nov 12 (NE), last Dec 15 (OR) — a 33-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/2025/11/Consumer-notification-letter-30.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Nov 12, 2025
Raw hash: 82edcfb9da5a17337e6170f6b6c591ac515f28c97baf075f6bf7c090fbffc31b

Linked disclosures

Regulatory filings (3) · sorted by filing gap

Reporting entityHamilton Construction Company

Victim entityHamilton Construction Company

Incidentdiscovered Jun 19, 2025

Stated responseTook steps to secure the network

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov