AT&T blamed China for the hack. Verizon said a 'small number of high-profile customers in government and politics were specifically targeted' by a nation-state threat actor.

U.S. telecom giants AT&T and Verizon say they have secured their networks after being targeted by the China-linked Salt Typhoon cyberespionage

This is the first time AT&T and Verizon have publicly acknowledged being affected by Salt Typhoon. For most customers, there’s little reason to worry. Verizon told TechCrunch that the hacking group behind the breach had targeted "a small number of high-profile customers in government." Still, the full scope of the breach remains unclear.