A security breach compromising data from the vast majority of AT&T cellular customers includes calls made to Canada, the telecom giant confirmed to Global News.
AT&T said Friday that the breach includes the data of nearly all of AT&T’s cellular customers, which includes more than 100 million individual customers in the U.S. and 2.5 million business accounts.
An AT&T spokesperson confirmed Friday that the data set in question includes calls to Canada. The breach includes aggregated metadata only, not the content of any calls, texts or social security or credit card information.
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 AT&T said that there are often ways, using publicly available online tools, to find the name associated with a specific telephone number.
The breach occurred in April earlier this year, but 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’s spokesperson says that the incident took place outside its network and the telecom’s own systems “were not breached.”
AT&T said that it currently doesn’t believe that the data is publicly available.
Also affected are customers of mobile virtual network operators using AT&T’s wireless network, as well as its landline customers interacted with those cellular numbers.
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 company continues to cooperate with law enforcement on the incident and that it understands that at least one person has been apprehended so far.
As for why customers are only hearing in July about a breach that happened in April, AT&T added in public filings that the U.S. Department of Justice twice affirmed that a “delay in providing public disclosure was warranted” amid ongoing investigations.
The compromised data also includes records from Jan. 2, 2023, for a very small number of customers. The records identify the telephone numbers an AT&T or MVNO cellular number interacted with during these periods. For a subset of records, one or more cell site identification number(s) associated with the interactions are also included.
It’s not the first data breach of this year for AT&T. In March the telecommunications giant said that a dataset found on the “dark web” contained information such as Social Security numbers for about 7.6 million current AT&T account holders and 65.4 million former account holders.
AT&T said at the time that it had already reset the passcodes of current users and would be communicating with account holders whose sensitive personal information was compromised.
Shares of AT&T Inc., based in Dallas, fell slightly on Friday.
— with files from The Associated Press