T-Mobile has severed its connection to the unnamed wireline provider, which it suspects may still be compromised.

T-Mobile says the Chinese "Salt Typhoon" hackers who recently compromised its systems as part of a series of telecom breaches first hacked into some of its routers to explore ways to navigate laterally through the network.

This morning, a report from Bloomberg states that T-Mobile engineers spotted suspicious behavior on the carrier's network devices that tipped off the carrier that it was under attack. Jeff Simon, T-Mobile 's chief security officer,

Salt Typhoon deployed various methods to break into telecommunications firms that went far beyond a singular run-of-the-mill credential-stealing attempt, according to a person familiar.

A recent confirmed T-Mobile hack has been attributed to Salt Typhoon, the Chinese cyber espionage team that also breached Verizon and AT&T earlier in the year. That means the hackers were able to penetrate all three of the country's major mobile carriers in 2024.