National security officials meet with US telecom execs to share intel on Chinese cyber-espionage campaign, White House says

(CNN) — Top telecom executives met with US national security officials at the White House on Friday as concerns mount over a long-running Chinese cyber-espionage campaign that has targeted some of the most senior US political figures in the country.

The hackers burrowed deep into some major US telecom providers to spy on phone calls and text messages and have proved difficult to kick out of some networks, people briefed on the matter said.

The meetings were a chance for telecom executives to advise the government on how it could boost its defenses against sophisticated hacks, according to the White House. The groups also shared intelligence on the operation with one another.

The hack is shaping up to be one of the biggest cyber and national security challenges facing the incoming Trump administration.

In another indicator of the growing concerns about the cyber-espionage campaign, an all-senators classified briefing is scheduled for December 4, after Congress returns from recess next month, according to a Senate aide.

The hack is “by far” the “worst telecom hack in our nation’s history,” Sen. Mark Warner, Democrat of Virginia and chairman of the intelligence committee, told CNN.

But the full scope of the hack, who it affects and its impact on national security are still being investigated.

The FBI has notified fewer than 150 victims, most in the Washington, DC, area, according to Warner. But all of those victims have likely called or sent texts to numerous people, meaning the number of records accessed by the hackers is likely far greater. The hackers could listen to the calls of specific targets for certain periods of time, according to Warner.

US officials and private cyber experts are keeping a running tally of the number of telecom firms breached. US broadband and internet providers AT&T, Verizon and Lumen have all been targeted in the hacking effort, CNN previously reported.

The hackers have targeted the phone communications of senior figures in both the Republican and Democratic parties, including President-elect Donald Trump, Vice President-elect JD Vance, Jared Kushner and Eric Trump, CNN has previously reported.

China has denied the hacking allegations.

US intelligence agencies also have vast hacking capabilities and have targeted China’s telecommunications sector, according to documents leaked by former National Security Agency contractor Edward Snowden over a decade ago.

US officials have sounded the alarm for years about China’s hacking program, which FBI Director Christopher Wray says is bigger than those of all other major countries combined.

But those warnings have grown more dire over the past year as concerns mount about a possible Chinese invasion of Taiwan.

Chinese government-linked hackers “will not and are not stopping because it is part of their overarching national objectives, and cyber has become one of their most powerful levers of national power,” Morgan Adamski, executive director of US Cyber Command, the military’s offensive and defensive cyber unit, said in a speech Friday.

The US government, including Cyber Command, has carried out offensive and defensive operations that are focused on “degrading and disrupting” China’s cyber operations worldwide, Adamski said at the CYBERWARCON conference in Arlington, Virginia.

This story has been updated with additional information.

CNN’s Morgan Rimmer contributed to this report.