MalwareFinancial ServicesFinanceRansomwareData EncryptedTargetedPIIIdentity (basic)LowContained

Tri Counties Bank

bd_3f1547cf3ba03ec1 · schema v1 · pii pii-v1

Severity

Low

Discovered

Feb 7, 2023

Filed

Oct 12, 2023

To disclose

35 weeks

Affected

91state residents only

Linked

11 filings

Confidence

64%

Full breach record for Tri Counties Bank →

Tri Counties Bank notified Montana residents of a cybersecurity incident discovered on February 7, 2023. Malware infected the internal bank network, potentially allowing unauthorized access to systems storing personal information between Feb 7-8, 2023. Impacted data included names. No evidence of identity theft was found. The bank shut down systems, engaged law enforcement, and offered 24 months of credit monitoring.

J jump to incidentP pin to compareR raw source

Incident timeline

discovery → filing · 35 weeks / 247 days

Feb 7, 2023

Begins

Feb 7, 2023

Discovered

Oct 12, 2023

Filed

vs. sector median

+27 wks slower

This filing is one of 11 about the same incident.View merged incident

Linked disclosures

Why this link?

Ransomware claims (1)

Leak Siteblack_bastabd_8a1c05db9a0376c62023-03-19 · +206dVerified by operator

Regulatory filings (9) · sorted by filing gap

Maine State AGbd_201ae7fa1e3c8a632023-10-12Verified by operator
Indiana State AGbd_459843a2f6e73e1c2023-10-12Verified
Massachusetts State AGbd_c631857751f1f3bd2023-10-12Verified by operator
California State AGbd_f2b2a26ac629eb7b2023-10-12Candidate

Show 5 more filings ↓up to 41d gap

SEC 8-Kbd_1297d2dd698bf7122023-10-13 · +1dCandidate
Maine State AGbd_0119439d398a4f922023-11-22 · +41dVerified
New Hampshire State AGbd_3d1dd695dbfc9eb92023-11-22 · +41dVerified by operator
California State AGbd_9d8a5b82fc79f5002023-11-22 · +41dVerified by operator
Vermont State AGbd_af220720d4d002912023-11-22 · +41dVerified by operator

Name: Tri Counties Bank
norm: tri counties bank
Domain: tcbk.com

Name: Tri Counties Bank
norm: tri counties bank
Domain: tcbk.com
Industry: Financial Servicesllm

Discovered: Feb 7, 2023
Breach occurred: Feb 7, 2023 – Feb 8, 2023
Undetected for: 0 daysoccurrence → discovery
Materiality determined: —
Notification sent: Oct 12, 2023
Affected individuals: 91state-resident count only
Data types: PIIIdentity (basic)
Attack vector: Unknown
MITRE ATT&CK: T1486 Data Encrypted for ImpactT1078 Valid Accounts
Threat actor: External
Regulator citations: notified applicable regulatory authorities

During the incident: Shut down our networked systems
Launched an investigation
Promptly notified law enforcement
Confirming the security of our systems
Reviewing the contents of relevant data for sensitive information
Notifying impacted individuals associated with that sensitive information
Notified applicable regulatory authorities
Offering 24 months of access to credit monitoring services through Experian at no cost
Changes made: Offering 24 months of access to credit monitoring services through Experian at no cost
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 35 weeks(247 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 10 filings · 7 states

View merged incident ↗

Maine State AGOct 12 · first

Indiana State AGOct 12 · first

Massachusetts State AGOct 12 · first

California State AGOct 12 · first

Montana State AGOct 12 · first · this page

SEC 8-K+1d

Maine State AG+41d

New Hampshire State AG+41d

California State AG+41d

Vermont State AG+41d

Pattern: first filing Oct 12 (ME), last Nov 22 (VT) — a 41-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-764.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 12, 2023
Raw hash: 1203206567b5b139e41815c14ca108d5d404b8db9bf28903b2fc457f3eca6c7e

Linked disclosures

Ransomware claims (1)

Regulatory filings (9) · sorted by filing gap

Reporting entityTri Counties Bank

Victim entityTri Counties Bank

Incidentdiscovered Feb 7, 2023

Stated responseShut down our networked systems

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov