Lumen’s confirmation comes after U.S. telecom giants AT&T and Verizon confirmed to TechCrunch that they had also secured their networks following their breaches. T-Mobile, another Salt Typhoon target, said last month that it had no evidence of hackers still in its systems.

Three months after reports surfaced about a cyberattack, called Salt Typhoon, targeting internet service providers and US wiretapping infrastructure, two of the largest telecom companies say they've made progress securing their networks against the threat.

The Chinese-linked Salt Typhoon cyberespionage operation targeted AT&T and Verizon's systems, but the wireless carriers' U.S. networks are now secure as they work with law enforcement and government officials,