T-Mobile Said to Have Caught Hackers Early, Averting Leak (1)

T-Mobile US Inc. was able to contain a recent network breach before it reached customers’ phones, according to people familiar with the matter.

Hackers accessed edge-routing infrastructure and gained unauthorized access to a limited number of devices, including a T-Mobile-owned-and-operated router, according to the people, who asked not to be identified discussing nonpublic information. When T-Mobile detected the suspicious activity, it booted the hackers from its systems.

The company detected reconnaissance activity aimed at reaching deeper layers of the network, but customer data wasn’t accessed because T-Mobile caught the intrusion at such an early stage, the people said.

T-Mobile knows ...