Data of nearly all AT&T customers downloaded to a third-party platform in a 2022 security breach

The data of nearly all customers of the telecommunications giant AT&T was downloaded to a third-party platform in a 2022 security breach, the company said Friday, in a year already rife with massive cyberattacks.

The breach hit customers of AT&T's cellular customers, customers of mobile virtual network operators using AT&T’s wireless network, as well as its landline customers interacted with those cellular numbers.

A company investigation determined that compromised data includes files containing AT&T records of calls and texts between May 1, 2022 and Oct. 31, 2022.

AT&T has more than 100 million customers in the U.S. and almost 2.5 million business accounts.

The company said Friday that it has launched an investigation and engaged with cybersecurity experts to understand the nature and scope of the criminal activity.

“The data does not contain the content of calls or texts, personal information such as Social Security numbers, dates of birth, or other personally identifiable information,” AT&T said Friday.

The compromised data also doesn’t include some information typically seen in usage details, such as the time stamp of calls or texts, the company said. The data doesn’t include customer names, but the AT&T said that there are often ways, using publicly available online tools, to find the name associated with a specific telephone number.

AT&T said that it currently doesn’t...