China-linked APT Salt Typhoon has breached telcos in dozens of countries

China-linked APT group Salt Typhoon has breached telecommunications companies in dozens of countries, US govt warns.

President Biden’s deputy national security adviser Anne Neuberger said that China-linked APT group Salt Typhoon has breached telecommunications companies in dozens of countries.

The Wall Street Journal reported that the senior White House official revealed that at least eight U.S. telecommunications firms were compromised in the attack.

The Salt Typhoon hacking campaign, active for 1–2 years, has targeted telecommunications providers in several dozen countries, according to a U.S. official.

“At this time, we don’t believe any classified communications have been compromised,” Neuberger said.

The deputy national security adviser said China accessed extensive metadata from targeted Americans while seeking specific communications, focusing regionally on government and political figures.

The White House aims to mandate minimum cybersecurity practices for telecoms, including secure configurations, anomaly monitoring, and strong key management, similar to rules in other critical infrastructures.

“We believe that if the companies had in place minimum [security] practices … that would make it far riskier, harder, and costlier for the Chinese to gain access and maintain access,” the senior administration official added.

The Biden administration prioritizes safeguarding tech and telecom infrastructure from PRC-linked cyber espionage operations and other foreign threats to protect U.S. national security.The Commerce Department’s tech security office is preparing measures to address risks from IT and communications transactions linked to China, Neuberger stated.

This week Australia, Canada, New Zealand, and the U.S. issued a joint advisory to warn of People’s Republic of China (PRC)-linked cyber espionage targeting telecom networks.

“The Cybersecurity and Infrastructure Security Agency (CISA), National Security Agency (NSA), Federal Bureau of Investigation (FBI), Australian Signals Directorate’s (ASD’s) Australian Cyber Security Centre (ACSC), Canadian Cyber Security Centre (CCCS), and New Zealand’s National Cyber Security Centre (NCSC-NZ) warn that People’s Republic of China (PRC)-affiliated threat actors compromised networks of major global telecommunications providers to conduct a broad and significant cyber espionage campaign.” reads the joint advisory.

The government agencies released a guide that advises telecom and critical infrastructure defenders on best practices to strengthen network security against PRC-linked and other cyber threats.

“identified exploitations or compromises associated with these threat actors’ activity align with existing weaknesses associated with victim infrastructure; no novel activity has been observed.” continues the advisory.

The agencies recommend robust measures to protect enterprise networks against cyber threats. These include scrutinizing network device configurations, implementing advanced monitoring solutions, and restricting internet exposure of management traffic. Enhancing secure logging, isolating device management, and enforcing strict access control lists (ACLs) are key strategies.

Strong segmentation with firewalls and DMZs, securing VPN gateways, and ensuring encrypted traffic with TLS v1.3 are essential for protecting data. Disabling unnecessary protocols and services, avoiding default passwords, and verifying software integrity bolster resilience. Regular port scans and updates for end-of-life systems ensure proactive defense.

Organizations should adopt secure password storage, phishing-resistant MFA, session token limits, and Role-Based Access Control (RBAC). Together, these measures reduce vulnerabilities, disrupt intrusion attempts, and strengthen network defenses.

The FBI and CISA continue investigating a large-scale cyber-espionage campaign by China-linked threat actors targeting U.S. telecoms, compromising networks to steal call records and access private communications, mainly of government and political figures.

The US agencies confirmed that Chinese threat actors have compromised the private communications of a “limited number” of government officials following the compromise of multiple U.S. broadband providers. The cyber spies stole information belonging to targeted individuals that was subject to U.S. law enforcement requests pursuant to court orders.

“The US government’s continued investigation into the People’s Republic of China (PRC) targeting of commercial telecommunications infrastructure has revealed a broad and significant cyber espionage campaign.” reads the joint statement issued by CISA and FBI.

“Specifically, we have identified that PRC-affiliated actors have compromised networks at multiple telecommunications companies to enable the theft of customer call records data, the compromise of private communications of a limited number of individuals who are primarily involved in government or political activity, and the copying of certain information that was subject to U.S. law enforcement requests pursuant to court orders. We expect our understanding of these compromises to grow as the investigation continues.”

In September, the Wall Street Journal reported that China-linked APT group Salt Typhoon (also known as FamousSparrow and GhostEmperor) breached U.S. broadband providers, including Verizon, AT&T, and Lumen Technologies, potentially accessing systems for lawful wiretapping and other data.

The security breach poses a major national security risk. The WSJ states that the compromise remained undisclosed due to possible impact on national security. Experts believe that threat actors are aimed at gathering intelligence.

“A cyberattack tied to the Chinese government penetrated the networks of a swath of U.S. broadband providers, potentially accessing information from systems the federal government uses for court-authorized network wiretapping requests.” reported the WSJ.

“For months or longer, the hackers might have held access to network infrastructure used to cooperate with lawful U.S. requests for communications data, according to people familiar with the matter, which amounts to a major national security risk.”

The Salt Typhoon group targeted surveillance systems used by the US government to investigate crimes and threats to national security, including activities carried out by nation-state actors.

The investigation into the breaches of the U.S. broadband providers is still ongoing, government experts are assessing its scope.

Experts suspect the state-sponsored hackers have gathered extensive internet traffic and potentially compromised sensitive data.

This attack is the latest incident linked to China’s expansive espionage strategies.

U.S. officials are increasingly concerned about Chinese cyber efforts to infiltrate critical infrastructure. Intelligence experts believe that security breaches like this could enable disruptive attacks during potential future conflicts.

The Salt Typhoon campaign is part of this broader strategy. Experts are still investigating the origins of the attack and whether threat actors compromised Cisco routers.

T-Mobile detected recent infiltration attempts but confirmed no unauthorized system access occurred, and no sensitive data was compromised.

The carrier is investigating reports that are linking it to “Salt Typhoon” cyberattacks tied to PRC-linked cyber espionage.

“Like the entire telecommunications industry, T-Mobile has been closely monitoring ongoing reports about a series of highly coordinated cyberattacks by bad actors known as “Salt Typhoon” that are reported to be linked to Chinese state-sponsored operations. Many reports claim these bad actors have gained access to some providers’ customer information over an extended period of time – phone calls, text messages, and other sensitive information, particularly from government officials. This is not the case at T-Mobile.” reads the report published by the telecommunications company. “To clear up some misleading media reports, here is what we’re currently seeing, much of which we believe is different from what is being seen by other providers.”

The carrier determined that the attacks originated from a wireline provider’s network that was connected to its systems.

The U.S. Telecom giant is not aware of instances of prior attempts like this.

The company’s defenses safeguarded customer data and services, blocking the attack. Connectivity to a compromised provider was interrupted, and T-Mobile notified industry and government leaders. The telco firm lacks conclusive attribution to Salt Typhoon or other APT groups.

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Pierluigi Paganini

(SecurityAffairs – hacking, APT)

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