Suspected data leak of AT&T exposes 70 million people, company finally confirms

A data leak involving more than 70 million records supposedly linked to AT&T is reported by researchers at vx-underground on the Breached forum.

The leak appears to be a re-surfacing of a data breach from 2021. The individual responsible for the leak, operating under the alias MajorNelson, has claimed that the data, comprising 73,481,539 records, was acquired by the hacker group @ShinyHunters from an unnamed AT&T division in 2021. AT&T, however, has consistently denied that any data theft occurred from its systems.

The leaked dataset includes:

• names,
• addresses,
• mobile phone numbers,
• encrypted dates of birth,
• encrypted social security numbers,
• other internal details.
• update - encrypted passwords

Decrypted birth dates and social security numbers have been made accessible in the leaked files.

Researchers have validated some the leaked data and confirmed it pertains to real persons and at least part of the data is not publicly available.It remains uncertain whether the data originated from AT&T directly or from a third-party organization associated with the company.

The exposure of this data could potentially lead to targeted phishing attacks, including SMS and email scams, as well as SIM swapping attacks. Customers are advised to exercise caution with any communications claiming to be from AT&T and to verify such contacts directly with the company.

Update - AT&T has acknowledged the data breach impacting 73 million current and former customers, contradicting their previous denials. The breach, seemingly originating from a 2019 dataset, involves 7.6 million current and 65.4 million former account holders, including leaked security passcodes. This follows claims by Shiny Hunters in 2021 about selling stolen AT&T customer data, which AT&T initially denied. The acknowledgment came after the data reappeared in 2024.

AT&T has reset the passcodes of millions of customer accounts following the acknowledgement of the data breach. This action was taken after TechCrunch alerted AT&T that the leaked data contained encrypted passcodes and there is a potential risk of unauthorized account access from the leaked data.

As of 10th of April 2024, AT&T is notifying 51 million former and current customers, warning them of a data breach that exposed their personal information on a hacking forum. The company has still not disclosed how the data was obtained.