Was TMobile hit by ransomware?

TMobile was listed by the BYOD ransomware operation (United States), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the BYOD ransomware group?

BYOD is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the TMobile breach?

BYOD published data attributed to TMobile. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

← All victims

T-Mobile US, Inc.

listed as TMobile · Claimed by BYOD · listed 5 hours ago

Today

Age

since listed · data leaked

Status timeline

ListedOct 7, 2026
Data leakeddate unknown

At a glance

Group: BYOD
Status: Data leaked
Country: United States
Sector: Technology
Listed on leak site: Oct 7, 2026

About the victim

AI dossier — public-source company profile

T-Mobile US is a major wireless telecommunications carrier operating in the United States. The company provides mobile phone services, data, and related telecommunications solutions to millions of consumers and businesses.

Industry: Wireless Telecommunications
Employees: 51000-100000
Founded: 1994

Attack summary

Severity: medium — Threat of data publication against a major telecommunications provider carrying sensitive customer data; however, no proof files or specific data inventory has been published yet, and the threat is still in negotiation phase.

BYOD claims to have compromised T-Mobile and threatens to publish exfiltrated data unless the company makes contact. No specific data categories or operational impact are detailed in the post.

medium

What the group claims

You're in big big trouble, oh no, what will you ever do in this situation? Well, we think you should get in touch with BYOD. We won't display what we have for the public to see, just yet, we'll give you the chance. Anyways, you know where to find us (contact tab). We will take you down when communication has been established between our team and yours.

Source

Indexed 5 hours ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

Is this your supplier? Your competitor? You?

Pro plans monitor your domain, corporate emails, and crypto wallets across every new ransomware leak-site post, breach dump and Telegram callout — alerts within 5 minutes.

Disclosure context

About BYOD

BYOD is a nascent ransomware group first observed in October 2026 with limited public documentation available from major threat intelligence sources at this time. The group has claimed or been attributed to three known victims, with targeting patterns indicating a focus on the Technology and Manufacturing sectors, with Malaysia and the United States representing their primary geographic targets. Due to the group's recent emergence and low victim count, no detailed attack methodology, tooling, or initial access vectors have been publicly documented by CISA, FBI, Mandiant, or equivalent reputable security research organizations as of this profile's compilation. No notable high-profile campaigns, record ransom demands, or law enforcement actions have been publicly attributed to BYOD, and their operational model — whether independent or RaaS-based — remains unconfirmed in open-source reporting. The group should be considered an emerging threat under active monitoring, with their targeting of dual geographies across Southeast Asia and North America warranting continued observation as their operational tempo and tactics may become clearer with additional victim disclosures or researcher attribution. The group has been linked to 7 public disclosures across our corpus. First observed on a leak site on October 5, 2026; most recent post October 7, 2026. The operation is currently active.

Timeline of this disclosure

October 7, 2026TMobile listed by BYOD on the group's public leak site

Other recent disclosures by BYOD

BYOD has been linked to 7 public victims on Darkfield. A sample of the most recent:

See the full BYOD dossier →

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 3,581 disclosures indexed across all operators we track. Geographically, TMobile is reported in United States, a country with 3,175 ransomware disclosures in our corpus.

If your organisation is affected

A listing by BYOD means TMobile appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Report the incident to your national CERT, CISA (United States), as required for your jurisdiction.
Monitor for the data appearing on BYOD's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.