Democratic Sen. Maria Cantwell has accused AT&T and Verizon of withholding crucial security documents related to Salt Typhoon, a 2024 cyberattack, intensifying concerns about the safety of U.S. telecommunications networks.
In a letter to Senate Cruz, Cantwell notes that the companies have not cooperated with requests to verify claims that their networks are now secure from Salt Typhoon and urges the CEOs to testify at a committee hearing.
Salt Typhoon is linked to a state-backed group from China and conducted extensive intrusions in 2024, exposing call and text metadata from millions of users and reportedly breaching internal wiretap systems used by the companies.
By late 2024 AT&T said there was no nation-state activity in their networks, and Verizon said the activity had been contained, but Cantwell’s 2025 inquiries prompted renewed government scrutiny. Mandiant, the security firm that reviewed the breaches for the firms, is reportedly withholding its findings after being directed by the operators.
Cantwell says Salt Typhoon may still be active in U.S. networks and could have accessed congressional staff email accounts; she calls for a Senate oversight hearing where AT&T and Verizon chiefs can publicly account for the incident and ongoing risks. The FBI previously warned the group targeted hundreds of organizations across more than 80 countries.
Salt Typhoon remains a major global threat to Western companies, and Cantwell emphasizes the need for transparency and accountability to ensure Americans’ networks are not exposed to unacceptable risk.
