HackingFinancial ServicesFinanceVulnerability ExploitSupply Chain (3P Vendor)Data ExfiltratedCustomer Data InvolvedPIIIdentity (basic)MediumContained

Stockman Bank of Montana

bd_353f8ae784f3b6b8 · schema v1 · pii pii-v1

Severity

Medium

Discovered

May 31, 2023

Filed

Aug 8, 2023

To disclose

10 weeks

Affected

4,581state residents only

Linked

5 filings

Confidence

66%

Full breach record for Stockman Bank of Montana →

Stockman Bank notified customers of a cybersecurity incident involving its vendor, Progress Software. A vulnerability in the vendor's MOVEit file-sharing software was exploited by unauthorized individuals, leading to the exfiltration of personal information (names and other PII) from a small percentage of Stockman Bank customers. The bank engaged forensic investigators, secured its systems, and offered one year of complimentary credit monitoring via Experian IdentityWorks.

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Incident timeline

discovery → filing · 10 weeks / 69 days

May 31, 2023

Discovered

Aug 8, 2023

Filed

vs. sector median

+1 wks slower

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

Part of Progress Software Corporation supply-chain incident (2023) — a supply-chain cascade affecting multiple organizations.View cascade →

Linked disclosures

Why this link?

Regulatory filings (4) · sorted by filing gap

New Hampshire State AGbd_035aefcad4f9f0442023-08-08Verified
Maine State AGbd_3facb6f42c9113c12023-08-08Verified
Massachusetts State AGbd_78096caa5f6eb5012023-08-08Verified
Indiana State AGbd_6ea7a09b7301a8c32023-08-07 · +1dVerified

Name: Stockman Bank of Montana
norm: stockman bank of montana

Name: Stockman Bank of Montana
norm: stockman bank of montana
Industry: Financial Servicesllm

Discovered: May 31, 2023
Materiality determined: —
Notification sent: Jul 28, 2023
Affected individuals: 4,581state-resident count only
Data types: PIIIdentity (basic)
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1041 Exfiltration Over C2 Channel
Threat actor: ExternalFinancial
Initial access: exploit_public_facing

During the incident: Restricting access to the MOVEit server
Implementing Progress Software’s recommended mitigation steps
Putting in place further mitigations identified internally to secure our MOVEit system
Examining other systems in our environment
Engaged a forensic investigation firm to conduct a full-scale technical investigation
Offering you a complimentary one-year membership of Experian’s® IdentityWorks
Changes made: Restricting access to the MOVEit server
Implementing Progress Software’s recommended mitigation steps
Putting in place further mitigations identified internally to secure our MOVEit system
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 10 weeks(69 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 AGAug 7 · first

New Hampshire State AG+1d

Maine State AG+1d

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/OCP/Consumer-notification-letter-528.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Aug 8, 2023
Raw hash: 2494aca874e99b3675823636fe400d7b5103526815c0fb2ac1f87d557554e807

Linked disclosures

Regulatory filings (4) · sorted by filing gap

Reporting entityStockman Bank of Montana

Victim entityStockman Bank of Montana

Incidentdiscovered May 31, 2023

Stated responseRestricting access to the MOVEit server

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov