Verizon's Chief Legal Officer informed Reuters, "We have not observed any threat actor activity within Verizon's network for an extended period. After extensive efforts to address this situation, we can confirm that Verizon has successfully contained the activities related to this incident."
AT&T also released a statement indicating its collaboration with law enforcement and other telecom firms to investigate the breach. The company noted that it identified a limited number of instances where the attackers sought to gather foreign intelligence and where customer data was affected.
"Currently, we see no activity from nation-state actors within our networks. Our ongoing investigation suggests that the People's Republic of China focused on a small group of individuals of foreign intelligence interest," an AT&T representative stated.
In November, T-Mobile revealed that the Chinese hacking group known as "Salt Typhoon" had compromised some of its routers to explore lateral movement within its network. However, Chief Security Officer Jeff Simon emphasized that the company's cybersecurity measures thwarted the attack that originated from a connected wireline provider's network.
"Malicious actors did not gain access to sensitive customer information, including calls, voicemails, or texts. We promptly disconnected from the provider's network, which we believe was – and may still be – compromised," Simon remarked.
Anne Neuberger, the White House's deputy national security adviser for cyber and emerging technologies, informed reporters on Friday that the Chinese hacking campaign affected nine U.S. telecommunications companies. Earlier this month, she also disclosed in a press briefing that the Chinese hackers had infiltrated carriers in numerous other countries.
The U.S. government is reportedly preparing to prohibit China Telecom's remaining operations in the United States as a reaction to recent telecom hacks. Additionally, there is consideration of banning TP-Link routers if investigations reveal that their deployment poses a national security threat.
Furthermore, FCC Chairwoman Jessica Rosenworcel emphasized that the agency would take "urgent" measures to mandate that U.S. carriers enhance the security of their infrastructure. U.S. Senator Ron Wyden from Oregon has also introduced a new bill aimed at fortifying the networks of American telecommunications companies.
The Salt Typhoon cyber-espionage group, also known by various names including Earth Estries, FamousSparrow, Ghost Emperor, and UNC2286, has been active since at least 2019 and is recognized for infiltrating telecom firms and government organizations across Southeast Asia.