HackingOtherStolen CredentialsCustomer Data InvolvedIdentity (basic)Government IDMediumContained

MasterCorp

bd_987c1d95566b0a3c · schema v1 · pii pii-v1

Severity

Medium

Discovered

Mar 31, 2023

Filed

May 30, 2023

To disclose

9 weeks

Affected

Not disclosed

Linked

3 filings

Confidence

66%

Full breach record for MasterCorp →

MasterCorp, Inc. notified consumers of a data breach detected on March 31, 2023. An unauthorized party accessed the network between March 30-31, 2023, potentially removing files containing names and Social Security numbers. MasterCorp contained the threat, engaged external cybersecurity professionals, and is offering complimentary credit monitoring services to affected individuals.

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Vermont clock⏱ VT AG >14 bday9 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 1 days

discovery → filing · 9 weeks / 60 days

Mar 30, 2023

Begins

Mar 31, 2023

Discovered

May 30, 2023

Filed

vs. sector median

+1 wks slower

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

A leak claim by black_basta about this victim predates this filing by 32 days.View originating leak claim

Linked disclosures

Why this link?

Ransomware claims (1)

Leak Siteblack_bastabd_f7a0a5ed0c8701332023-04-27 · +32dVerified by operator

Regulatory filings (1) · sorted by filing gap

Massachusetts State AGbd_e8cd3a1ed548572b2023-05-31 · +1dVerified by operator

Name: MasterCorp
norm: mastercorp
Domain: mastercorp.com

Name: MasterCorp
norm: mastercorp
Domain: mastercorp.com
Industry: Otherllm

Discovered: Mar 31, 2023
Breach occurred: Mar 30, 2023 – Mar 31, 2023
Undetected for: 1 dayoccurrence → discovery
Materiality determined: May 30, 2023
Notification sent: May 30, 2023
Affected individuals: Not disclosed
Data types: Identity (basic)Government ID
Data elements: Social Security number
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Initial access: valid_credentials

During the incident: Contained the threat by disabling all unauthorized access to our network
Commenced a prompt and thorough investigation
Working very closely with external cybersecurity professionals
Offering a complimentary membership of Single Bureau Credit Monitoring/Single Bureau Credit Report/Single Bureau Credit Score services at no charge
Providing proactive fraud assistance
Changes made: Continually evaluate and modify practices to enhance the security and privacy of your information
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 9 weeks(60 days from discovery to filing)
Compliance flags: VT AG >14 bdayLeak >30d
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Vermont State AGMay 30 · first · this page

Massachusetts State AG+1d

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://ago.vermont.gov/document/2023-05-30-mastercorp-data-breach-notice-consumers
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: May 30, 2023
Raw hash: a2d54875987872594d4a1457b442cd29a456e9c0c521a3961d8795ad561e69c0

Linked disclosures

Ransomware claims (1)

Regulatory filings (1) · sorted by filing gap

Reporting entityMasterCorp

Victim entityMasterCorp

Incidentdiscovered Mar 31, 2023

Stated responseContained the threat by disabling all unauthorized access to our network

ComplianceVT AG >14 bday

Extraction provenanceno artifact recorded

Source provenanceago.vermont.gov