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Cyber Threat
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Ransomware victim Technology

AT&T

Listed by Endzone on · organisation based in United States

att.com

Disclosed
Sep 18, 2026
Leak-site listing date
Threat group
Endzone
10 victims listed
Country
United States
#1 most targeted
Sector
Technology

ThreatAI analysis

Compiled from this incident record and the threat intelligence profile for Endzone. Figures and technique mappings are quoted from the source data, not inferred.

Endzone listed AT&T on its dark web leak site on 18 September 2026. AT&T is based in United States and operates in the Technology sector.

About the Endzone group

Endzone has listed 6 victims since September 2026.

Incident analysis

AT&T was listed by Endzone ransomware, a group with 10 victims recorded in this database. The listing appeared on the group's leak site on September 18, 2026.

AT&T is based in United States and operates in the Technology sector. United States ranks #1 worldwide for ransomware disclosures, with 10,292 victims in this database.

Sector context. Technology companies hold intellectual property, customer data, and source code — all highly valuable assets. A successful ransomware attack can also put downstream customers at risk through supply chain exposure.

Endzone typically follows a double extortion model: data is exfiltrated from the victim's systems before files are encrypted, so the victim faces two demands at once — pay to restore access, and pay to keep stolen data unpublished. The leak site, where this listing appeared, is the lever for the second demand.

Source. Public leak-site disclosures aggregated via the ransomware.live API. The disclosure date is when the listing was published, which can differ from the date of compromise. This site does not publish or link to stolen data. Last updated .

Frequently asked questions

Was AT&T attacked by ransomware?

Yes. AT&T was listed as a victim of the Endzone ransomware group on September 18, 2026. The organisation is based in United States and operates in the Technology sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked AT&T?

AT&T was attacked by Endzone ransomware. Endzone is one of the most active ransomware groups, having claimed 10 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the AT&T ransomware attack occur?

The ransomware attack on AT&T was disclosed on September 18, 2026. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the AT&T ransomware attack?

The specific data stolen from AT&T has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Technology organisation, AT&T likely held source code, intellectual property, and customer data.

How can organisations protect against Endzone attacks?

To defend against Endzone and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.