U.S. Telecoms Launch C2 ISAC After Salt Typhoon Breached Carrier Networks

Major U.S. telecommunications providers have formed the Communications Cybersecurity Information Sharing and Analysis Center (C2 ISAC) to strengthen real-time threat sharing and collective defense after the China-linked Salt Typhoon campaign compromised carrier networks in the United States and abroad. The intrusions, described by Sen. Mark Warner as the worst telecom hack in U.S. history, affected multiple major providers including AT&T, Verizon, Lumen Technologies, T-Mobile, and others, with investigators saying the activity has been ongoing since at least 2019 and there is still no clear public evidence the threat actors have been fully removed from communications networks.

Officials and reporting said the espionage campaign enabled attackers to move between telecom networks, exfiltrate large volumes of data, and in some cases listen to audio calls in real time while targeting high-value intelligence, government, and political communications. Investigators also found breaches of U.S. lawful intercept systems used for court-ordered surveillance, while a separate suspected China-linked compromise of an FBI surveillance system likely exposed phone numbers of monitored targets; the campaign has also been linked to exploitation of vulnerabilities in Cisco routers to gain access to telecom infrastructure.