The dark web is a term for cyberspace with hidden content that is often used for malicious activities. AT&T said the breach occurred two weeks ago, with data from 2019 or later, and even before 2019. About 7.6 million current customers and about 65.4 million former customers of the US carrier were affected.

AT&T is trying to determine whether the data was leaked from the company or from one of its suppliers.

AT&T has no evidence that any unauthorized access to its systems has resulted in data loss. AT&T is also contacting customers to ask them to change their passwords.