Suspicious behavior on T-Mobile US Inc.’s network devices tipped off the company to a breach that was potentially part of a sprawling cyber-espionage campaign that has raised urgent questions about the exposure of a critical sector of the economy.

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,

T-Mobile, one of America's largest wireless carriers, has confirmed it was compromised in a recent wave of sophisticated cyberattacks targeting U.S. telecom companies.

T-Mobile has revealed it was among the telecom providers hacked by a group reportedly tied to the Chinese government.

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