The China-backed hacking group Salt Typhoon remains inside the networks of some of America's largest phone and internet providers, with unclear intentions.
The hackers have accessed real-time unencrypted calls, text messages, and metadata of targeted telecom companies, including AT&T, Verizon, and Lumen.
U.S. officials suspect the hacks are part of a wide-ranging spying operation by China, targeting U.S. officials and senior Americans.
To combat Chinese hackers, the FBI and CISA recommend using encrypted messaging apps like Signal and WhatsApp for secure communication.