The hackers used their access to telecom networks to target the metadata of a large number of customers, including information on the dates, times and recipients of calls and texts.

Federal authorities on Tuesday urged telecommunication companies to boost network security following a sprawling Chinese hacking campaign that gave officials in Beijing access to private texts and phone conversations of an unknown number of Americans.

At least eight U.S. telecommunications firms were compromised in the attack, a senior White House official said.

U.S. officials say they're investigating Chinese government-affiliated hackers who compromised the networks of of U.S. communication companies and were able to intercept private communications of people affiliated with the U.

US officials are still trying to help major telecom providers evict Chinese government-backed hackers from their networks and don’t have a timeline for when that will be done, officials said Tuesday.