HackingTelecom & MediaInformationStolen CredentialsPhishingData ExfiltratedData PublishedCustomer Data InvolvedIdentity (basic)Government IDPIIHighContained

AT&T INC.

bd_9c10bf1a6486d810 · schema v1 · pii pii-v1

Severity

High

Discovered

Mar 26, 2024

Filed

Apr 9, 2024

To disclose

14 days

Affected

70,747state residents only

Linked

13 filings

Confidence

64%

Full breach record for AT&T INC. →19 incidents on file

AT&T Inc. notified Montana residents that customer information was compromised after appearing in a dataset released on the dark web on March 17, 2024. AT&T determined on March 26, 2024, that data including names, SSNs, and account details was involved. AT&T reset passcodes and offered one year of credit monitoring via Experian.

J jump to incidentP pin to compareR raw source

Leak gap clock✗ Leak >180d14 days discovery → filing

Incident timeline

undetected · 9 days

discovery → filing · 14 days

Mar 17, 2024

Begins

Mar 26, 2024

Discovered

Apr 9, 2024

Filed

This filing is one of 13 about the same incident.View merged incident

A leak claim by everest about this victim predates this filing by 529 days.View originating leak claim

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

South Carolina State AGbd_54dc2a4241a0af372024-04-09Candidate
California State AGbd_962bc7783c26b3452024-04-09Verified
Vermont State AGbd_ae9a0cefc958af772024-04-09Verified
Indiana State AGbd_ff7d944ebd2888c92024-04-09Verified

Show 6 more filings ↓up to 94d gap

Washington State AGbd_2c04c4a158e44fd22024-04-10 · +1dVerified
Massachusetts State AGbd_36f4d420cf6fa07e2024-04-10 · +1dVerified
Oregon State AGbd_7534be63ba9185ec2024-04-10 · +1dVerified
New Hampshire State AGbd_79d7d9a7036db0e92024-04-15 · +6dVerified
Delaware State AGbd_5109fdbae81c15502024-04-25 · +16dVerified
SEC 8-Kbd_a4373d2af8bc759a2024-07-12 · +94dVerified

Showing first 10 of 12 linked disclosures.

Name: AT&T INC.
norm: at t
Domain: att.com

Name: AT&T INC.
norm: at t
Domain: att.com
Industry: Telecom & Mediallm

Discovered: Mar 26, 2024
Breach occurred: Mar 17, 2024
Undetected for: 9 daysoccurrence → discovery
Materiality determined: —
Notification sent: Apr 30, 2024
Affected individuals: 70,747state-resident count only
Data types: Identity (basic)Government IDPII
Data elements: Social Security numberDate of birth
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1566.002 Spearphishing LinkT1041 Exfiltration Over C2 Channel
Threat actor: ExternalFinancial
Initial access: valid_credentials

During the incident: Offering one year of complimentary credit monitoring, identity theft detection and resolution services provided by Experian’s® IdentityWorksSM
Reset your passcode
Launched a robust investigation supported by internal and external cybersecurity experts
Changes made: Regularly reviewing and updating the measures we take to protect your information
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 14 days(14 days from discovery to filing)
Compliance flags: Leak >180d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 10 states

View merged incident ↗

South Carolina State AGApr 9 · first

California State AGApr 9 · first

Vermont State AGApr 9 · first

Indiana State AGApr 9 · first

Montana State AGApr 9 · first · this page

Washington State AG+1d

Massachusetts State AG+1d

Oregon State AG+1d

New Hampshire State AG+6d

Delaware State AG+16d

SEC 8-K+94d

Pattern: first filing Apr 9 (SC), last Jul 12 — a 94-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Cascade drawn from the first 10 linked disclosures of 12 — the full spread may be wider.

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-1273.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 9, 2024
Raw hash: 3d5ee206177aaab57385950c67a9f796d5c51a52ee1ac8cde946412286c5fde1

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityAT&T INC.

Victim entityAT&T INC.

Incidentdiscovered Mar 26, 2024

Stated responseOffering one year of complimentary credit monitoring, identity theft detection and resolution services provided by Experian’s® IdentityWorksSM

ComplianceLeak >180d

Extraction provenanceno artifact recorded

Source provenancedojmt.gov