HackingTelecom & MediaInformationStolen CredentialsCustomer Data InvolvedCredentialsIdentity (basic)LowContained

T-MOBILE US, INC.

bd_abc7db8579ef1ba6 · schema v1 · pii pii-v1

Severity

Low

Discovered

Mar 1, 2023

Filed

Apr 28, 2023

To disclose

8 weeks

Affected

1state residents only

Confidence

66%

Full breach record for T-MOBILE US, INC. →5 incidents on file

T-Mobile US, Inc. notified the New Hampshire Attorney General that a bad actor gained unauthorized access to limited information from a small number of T-Mobile accounts between late February and March 2023. One New Hampshire resident was affected. The compromised data included account PINs. T-Mobile reset the PINs, shut down access, and provided two years of free credit monitoring.

J jump to incidentP pin to compareR raw source

Incident timeline

undetected · 2 days

discovery → filing · 8 weeks / 58 days

Feb 27, 2023

Begins

Mar 1, 2023

Discovered

Apr 28, 2023

Filed

Tracked as a single-filing incident — the only disclosure on record for this event so far.Confirmed1 affectedView incident

Name: T-MOBILE US, INC.
norm: t mobile us

Name: T-MOBILE US, INC.
norm: t mobile us
Industry: Telecom & Mediallm

Discovered: Mar 1, 2023
Breach occurred: Feb 27, 2023 – Mar 31, 2023
Undetected for: 2 daysoccurrence → discovery
Materiality determined: —
Notification sent: Apr 28, 2023
Affected individuals: 1state-resident count only
Data types: CredentialsIdentity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: ExternalFinancial
Regulator citations: Provided notice to the Consumer Protection and Antitrust Bureau, Office of the Attorney General of New Hampshire
Initial access: valid_credentials

During the incident: Shut down the unauthorized access
Implemented controls to prevent reoccurrence
Reported this incident to law enforcement
Proactively reset your PIN
Offering you two years of free credit monitoring and identity theft detection services
Changes made: Implemented controls to prevent reoccurrence
Enhance security of your information
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 8 weeks(58 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

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://mm.nh.gov/files/uploads/doj/remote-docs/t-mobile-usa-20230428.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 28, 2023
Raw hash: 90eb9750e5f219e65a780ea68180aeb07ddf9edfcef0bc6555f643ef62bcd232

Reporting entityT-MOBILE US, INC.

Victim entityT-MOBILE US, INC.

Incidentdiscovered Mar 1, 2023

Stated responseShut down the unauthorized access

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancemm.nh.gov