Social EngineeringFinancial ServicesFinancePhishingStolen CredentialsCustomer Data InvolvedTargetedPIIIdentity (basic)LowContained

Cornerstone Bank

bd_a1a155190343bd40 · schema v1 · pii pii-v1

Severity

Low

Discovered

Jul 10, 2024

Filed

Nov 5, 2024

To disclose

17 weeks

Affected

152state residents only

Linked

3 filings

Confidence

66%

Full breach record for Cornerstone Bank →2 incidents on file

Cornerstone Bank notified Montana residents of a cybersecurity incident discovered on July 10, 2024, involving unauthorized access to a small number of employee email accounts via phishing. The bank engaged forensic specialists and federal law enforcement, offering 12-24 months of credit monitoring to affected individuals.

J jump to incidentP pin to compareR raw source

Incident timeline

discovery → filing · 17 weeks / 118 days

Jul 10, 2024

Discovered

Nov 5, 2024

Filed

vs. sector median

+8 wks slower

This filing is one of 3 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (2) · sorted by filing gap

Massachusetts State AGbd_8d890d7becda9f502024-11-05Verified
New Hampshire State AGbd_e70bac0b80922c9b2024-11-04 · +1dVerified

Name: Cornerstone Bank
norm: cornerstone bank

Name: Cornerstone Bank
norm: cornerstone bank
Industry: Financial Servicesllm

Discovered: Jul 10, 2024
Materiality determined: —
Notification sent: Oct 31, 2024
Affected individuals: 152state-resident count only
Data types: PIIIdentity (basic)
Attack vector: Phishing
MITRE ATT&CK: T1566.002 Spearphishing LinkT1078 Valid Accounts
Threat actor: ExternalFinancial
Regulator citations: reported this incident to federal law enforcement
Initial access: phishing_link

During the incident: Took swift action to secure our email system and network
Began working with third-party computer specialists to investigate the full nature and scope of the incident
Reported this incident to federal law enforcement
Engaged third-party forensic specialists to investigate this matter
Arranged for you to activate, at no cost to you, identity theft protection services through IDX
Changes made: Secured our email system and network
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 17 weeks(118 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 3 filings · 3 states

View merged incident ↗

New Hampshire State AGNov 4 · first

Massachusetts State AG+1d

Montana State AG+1d · 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://dojmt.gov/wp-content/uploads/2024/11/Consumer-notification-letter-25.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Nov 5, 2024
Raw hash: e8542f8bb50d372c97c495b3f68292dcde4cc7540b1fc16be00533c00a9a9178

Linked disclosures

Regulatory filings (2) · sorted by filing gap

Reporting entityCornerstone Bank

Victim entityCornerstone Bank

Incidentdiscovered Jul 10, 2024

Stated responseTook swift action to secure our email system and network

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov