AT&T Investigating Potential Data Breach Impacting More Than 70M Past And Current Customers

The telecommunications company does not yet know whether data recently discovered on the dark web came from a hack of its own systems or from a data breach at a vendor company.

AT&T is investigating a possible data breach after personal data from more than 70 current and former customers was discovered on the dark web.

On Saturday AT&T issued a statement saying that it had determined that “AT&T data-specific fields were contained in a data set released on the dark web approximately two weeks ago.”

The Dallas-based telecommunications giant said that based on a preliminary analysis the data set appears to be from 2019 or earlier and impacts approximately 7.6 million current AT&T account holders and approximately 65.4 million former account holders.

The company said the discovered data includes personal information such as social security numbers.

AT&T said it is not yet known whether the data originated from AT&T itself or from one of its vendors and that “the source of the data is still being assessed.

“Currently, AT&T does not have evidence of unauthorized access to its systems resulting in exfiltration of the data set,” the company said.

The company said it has “launched a robust investigation supported by internal and external experts” and is “communicating proactively with those impacted and will be offering credit monitoring at our expense where applicable.”

A news report from the Associated Press, posted Saturday, said that AT&T has already reset passcodes of current users. The AP story said that while the compromised data does not appear to include financial information and call history, it may include email and mailing addresses, phone numbers and birth dates, along with social security numbers and passcodes.

An NPR story, also posted Saturday, said the information within the compromised data set varies from person to person and said the discovered data also includes full names and AT&T account numbers.

AT&T said that the incident has not had a material impact on AT&T’s operations.

The data breach incident comes little more than a month after AT&T’s wireless network suffered a service outage on Feb. 22 that impacted thousands of its wireless customers. The company later blamed on “the application and execution of an incorrect process used while working to expand” the AT&T network.