President-elect Donald Trump will face the United States' biggest cyber challenge to date when he takes office, as Chinese hackers become more persistent and ruthless than ever, reports NBC News.

"I don't think there's any doubt that the risk of Chinese cyberattacks has gone up," said Adam Segal, who served as a senior cybersecurity adviser in the State Department last year. "And Chinese capabilities have seemed to have notably increased over the last four years."

A report published Thursday by Bloomberg said Chinese-state sponsored hackers in December breached U.S. Treasury Secretary Janet Yellen's computer and accessed unclassified files as part of a broader breach of the Treasury Department.

In October, reports surfaced of a Chinese-state linked cyberattack on major U.S. telecom providers that compromised sensitive wiretapping systems.

U.S. officials are still grappling with the fallout of that campaign, known as Salt Typhoon, which gave officials in Beijing access to private texts and phone conversations of an unknown number of Americans. A senior White House official said Friday that the number of telecommunications companies confirmed to have been affected by the hack has now risen to nine.

President Joe Biden issued an executive order Thursday aimed at strengthening the nation's cybersecurity and making it easier to go after foreign adversaries or hacking groups that try to compromise U.S. internet and telecommunication systems.

The order requires federal agencies to improve cybersecurity to protect against the threat posed by powerful quantum computers, which experts say could be used to easily break into many systems. That could have direct national security implications if a foreign adversary builds a computer sophisticated enough to break American codes.

But Brian Hughes, a Trump-Vance transition spokesperson, told NBC Trump will be more aggressive against China.

"For too long, our country has been on defense when it comes to cyberattacks," he said.

"The Trump administration is committed to imposing costs on private and nation state actors who continue to steal our data and attack our infrastructure," Hughes said.

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