FILE - A visitor walks past US multinational telecommunications AT&T logo during the Mobile World Congress (MWC), the telecom industrys biggest annual gathering, in Barcelona on February 26, 2024. (Photo by Pau Barrena/AFP via Getty Images)
AT&T said a data breach was found to have compromised various personal information for millions of customers on the "dark web."
The telecommunications giant said Saturday that the dataset contains information such as Social Security numbers for about 7.6 million current AT&T account holders and 65.4 million former account holders.
"If your information was impacted, you will be receiving an email or letter from us explaining the incident, what information was compromised, and what we are doing for you in response," the company said, adding that they’ve already reset the passcodes of some current users.
It is not known if the data "originated from AT&T or one of its vendors," AT&T added.
They said the compromised data is from 2019 or earlier and does not appear to include financial information or call history.
In addition to passcodes and Social Security numbers, it may include email and mailing addresses, phone numbers and birth dates.
It is not the first crisis this year for the Dallas-based company. An outage in February temporarily knocked out cellphone service for thousands of U.S. users. AT&T at the time blamed the incident on a technical coding error, not a malicious attack.
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This story was reported from Detroit. The Associated Press contributed.