AT&T believes the data, which was stolen in April, is no longer publicly available. Affected current and former customers will be notified by the company but can also check their status online.
AT&T says hackers stole data from “nearly all” of its cellular customers over several months in 2022 and downloaded it illegally onto a third-party cloud platform.
The Dallas-based telecommunications company announced the massive data breach in a regulatory filing and press release on Friday morning, which said it believes the data is no longer publicly available.
“AT&T has taken additional cybersecurity measures in response to this incident including closing off the point of unlawful access,” it added.
The company wrote that it first learned of the incident in April, but the U.S. Justice Department determined in May and again in June that “a delay in providing public disclosure was warranted” until now.
AT&T’s investigation found that an unspecified number of “threat actors” exfiltrated files in April containing the records of phone calls and text messages of “nearly all AT&T cellular customers” between May and October 2022, as well as a smaller number of customers on Jan. 2, 2023.
An AT&T spokesperson described the information taken as “aggregated metadata,” holding information about the calls and texts but not their contents.
