HackingFinancial ServicesFinanceStolen CredentialsCapture Stored DataData ExfiltratedTargetedIdentity (basic)Government IDFinancial accountPHIMediumContained

Heritage South Credit Union

bd_996422d1804d5880 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Feb 12, 2025

Filed

Mar 21, 2025

To disclose

5 weeks

Affected

1state residents only

Linked

3 filings

Confidence

66%

Full breach record for Heritage South Credit Union →

Heritage South Credit Union notified Montana residents of a data breach where an unauthorized third party accessed the network between Jan 7 and Feb 17, 2025. Suspicious activity was detected on Feb 12, 2025. Personal info including SSNs, driver's licenses, and financial account numbers may have been accessed. The credit union engaged forensic investigators and offered one year of Experian IdentityWorks.

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Incident timeline

undetected · 36 days

discovery → filing · 5 weeks / 37 days

Jan 7, 2025

Begins

Feb 12, 2025

Discovered

Mar 21, 2025

Filed

vs. sector median

3 wks faster

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

Linked disclosures

Why this link?

Ransomware claims (1)

Leak Siteembargobd_352c41f3a4c5524a2025-02-14 · +34dVerified by operator

Regulatory filings (1) · sorted by filing gap

Massachusetts State AGbd_e2b00daaaae6e0322025-03-21Verified by operator

Name: Heritage South Credit Union
norm: heritage south credit union
Domain: myhscu.com

Name: Heritage South Credit Union
norm: heritage south credit union
Domain: myhscu.com
Industry: Financial Servicesllm

Discovered: Feb 12, 2025
Breach occurred: Jan 7, 2025 – Feb 17, 2025
Undetected for: 36 daysoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: 1state-resident count only
Data types: Identity (basic)Government IDFinancial accountPHI
Data elements: Social Security numberDate of birth
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid AccountsT1119 Automated Collection
Threat actor: ExternalFinancial
Regulator citations: notified law enforcement
Initial access: valid_credentials

During the incident: Began an internal investigation
Notified law enforcement
Worked to secure our systems
Engaged a forensic security firm to assist with our investigation
Changes made: Enhancing our technical security measures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 5 weeks(37 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Massachusetts State AGMar 21 · first

Montana State AGMar 21 · first · 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/2025/04/Consumer-notification-letter-18.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Mar 21, 2025
Raw hash: b51f2e48e50250d73e37bc46068b9b5ed6da3726d7d91c0b4e7392073d15989a

Linked disclosures

Ransomware claims (1)

Regulatory filings (1) · sorted by filing gap

Reporting entityHeritage South Credit Union

Victim entityHeritage South Credit Union

Incidentdiscovered Feb 12, 2025

Stated responseBegan an internal investigation

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov