China Could Threaten Critical Infrastructure in a Conflict, N.S.A. Chief Says

China has been trying to find ways to gain access to critical infrastructure in the United States so that it can threaten those systems in the event of a conflict, the National Security Agency director said on Wednesday.

Gen. Timothy D. Haugh, who took the helm of the N.S.A. and the U.S. military’s Cyber Command in February, said that Beijing had stepped up its cyberefforts and that the United States, in response, was working harder to disrupt that activity.

Last year, U.S. officials uncovered an effort by China to gain access to critical infrastructure in Guam, home to U.S. military bases, and in the continental United States. Microsoft called the intrusions Volt Typhoon, after a Chinese network of hackers who often avoided using detectable malware and instead used stealthier techniques to enter wastewater systems and communication networks.

“What you see in Volt Typhoon is an example of how China has approached establishing access to put things under threat,” General Haugh said at a security conference at Vanderbilt University. “There is not a valid intelligence reason to be looking at a water treatment plant from a cyberperspective.”

General Haugh said China was securing access to critical networks ahead of a direct confrontation between the two countries. While he did not say specifically what that could involve, other American officials have said that if China gained access to critical infrastructure near military bases, it could disrupt or shut down systems to sow chaos and slow response time to a crisis in the Pacific or over Taiwan.

“They are sending a pretty clear signal of how they would use cyberspace in a crisis,” he said.

General Haugh said that Volt Typhoon was part of Beijing’s campaign to expand its global dominance. China, he said, is an “urgent military threat” and is increasing the sophistication of its cyberabilities.