Senators Ron Wyden and Eric Schmitt are calling on the Pentagon to investigate its own 'failure to secure its unclassified telephone communications from foreign espionage.'
The FBI and the Cybersecurity and Infrastructure Security Agency confirmed publicly on November 13 that the China-linked hacking group known as Salt Typhoon has been embedded in major United States telecom companies for more than a year, running a sophisticated espionage operation.
US officials have been investigating the espionage campaign for months which has reportedly targeted high-profile targets like president-elect Donald Trump and his campaign officials.
The senators attached to their letter two DOD white papers in which the Pentagon acknowledged that the telecoms it has contracts with have security vulnerabilities that could be exploited by foreign entities for surveillance.
T-Mobile was reportedly breached in the Salt Typhoon campaign, but has seen no signs of compromise.
T-Mobile has contracts with the Army, Air Force, Special Operations Command, and many other divisions of the DOD.
The senators provide evidence in their letter that US telecoms have worked with third-party cybersecurity firms to conduct audits of their systems related to the telecom protocol known as SS7 but have declined to make the results of these evaluations available to the Defense Department.
The Pentagon contracts with major US carriers for much of its telecom infrastructure.
T-Mobile's assertion that it did not suffer a breach in this instance is noteworthy.
The senators wrote, "We urge you to consider whether DOD should decline to renew these contracts, and instead renegotiate with the contracted wireless carriers, to require them to adopt meaningful cyber defenses against surveillance threats."