AT&T says outage to its U.S. cellphone network was not caused by cyberattack

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(Adobe Stock)

AT&T said the hourslong outage to its U.S. cellphone network Thursday appeared to be the result of a technical error, not a malicious attack.

The outage knocked out cellphone service for thousands of its users across the United States starting early Thursday before it was restored.

AT&T blamed the incident on an error in coding, without elaborating.

“Based on our initial review, we believe that today’s outage was caused by the application and execution of an incorrect process used as we were expanding our network, not a cyber attack,” the Dallas-based company said.

Outage tracker Downdetector noted that outages, which began at about 3:30 a.m., peaked at around 73,000 reported incidents. AT&T had more than 58,000 outages around noon in locations including Houston, Atlanta and Chicago.

Indianapolis was one of the top nine markets affected by the AT&T outages, according to Downdetector

AT&T is the country’s largest carrier, with more than 240 million subscribers.

By 9 p.m., the reports on AT&T’s network were fewer than 1,000.

Cricket Wireless, which is owned by AT&T, had more than 9,000 outages at one point but the reports had also tailed off later in the afternoon. Users of other carriers, including Verizon and T-Mobile, also reported issues but those companies said their networks were operating normally and the problems were likely stemming from customers trying to connect to AT&T users.

During the outage, some iPhone users saw SOS messages displayed in the status bar on their cellphones. The message indicates that the device is having trouble connecting to their cellular provider’s network, but it can make emergency calls through other carrier networks, according to Apple Support.

The Federal Communications Commission contacted AT&T about the outage and the Department of Homeland Security and FBI were also looking into it, National Security Council spokesman John Kirby said.

The FBI acknowledged it had been in touch with AT&T. “Should we learn of any malicious activity we will respond accordingly,” the agency said.

The outage also raised concerns on Capitol Hill.

“We are working to assess today’s disruption in order to gain a complete understanding of what went wrong and what can be done to prevent future incidents like this from occurring,” said a statement issued by Cathy McMorris Rodgers, a Washington Republican who chairs the House Energy and Commerce Committee, and Ohio Republican Bob Latta, chair of the Communications and Technology Subcommittee.

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5 thoughts on “AT&T says outage to its U.S. cellphone network was not caused by cyberattack

  1. “Error in coding” … AT&T has again demonstrated they lack the requisite procedures, processes and discipline when running a technical organization. This demonstrates again that AT&T lacks the requisite procedures not only to control who and when changes are made to a “production” or “live” environment. “Best practice” organizations tests any changes being made to a “production” environment, testing the changes “beginning to end” to ensure no unexpected changes will take down or make the “production” environment inoperable or degradate the service levels. And in the event that after all the testing, a problem does occur, you should have a pre-tested “roll back” process and procedure that you have tested in advance to enable a business to restore the “system” back to its previous settings and code configuration. Clearly AT&T management had none of the procedures, processes nor discipline in place which negatively impacted the service levels of an unknown number of customers. Thank goodness there were no serious medical situations that required telecommunication services to work.

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