By Shira Stein and Jennifer Jacobs | Bloomberg

The U.S. Health and Human Services Department suffered a cyber-attack on its computer system, part of what people familiar with the incident called a campaign of disruption and disinformation that was aimed at undermining the response to the coronavirus pandemic and may have been the work of a foreign actor.

“We are aware of a cyber incident related to the Health and Human Services computer networks, and the federal government is investigating this incident thoroughly,” John Ullyot, a spokesman for the National Security Council, said in a statement. “HHS and federal government cybersecurity professionals are continuously monitoring and taking appropriate actions to secure our federal networks.”

He said “HHS and federal networks are functioning normally at this time.”

While a foreign actor is suspected in the attack, the administration hasn’t yet confirmed who was behind it, according to a U.S. official.

The attack, which involved overloading the HHS servers with millions of hits over several hours, didn’t succeed in slowing the agency’s systems significantly, as was apparently intended, according to one of the people, who asked for anonymity to discuss details of the sensitive incident.

But action was taken to alert Americans once the government realized Sunday night that there had been multiple incidents of cyber intrusion and that false information also was being circulated, according to one of the people.

Just before midnight, the National Security Council issued a tweet warning without elaboration against “fake” text messages, according to one of the people.

“Text message rumors of a national #quarantine are FAKE,” the NSC said. “There is no national lockdown. @CDCgov has and will continue to post the latest guidance on #COVID19.”

Text message rumors of a national #quarantine are FAKE. There is no national lockdown. @CDCgov has and will continue to post the latest guidance on #COVID19. #coronavirus — NSC (@WHNSC) March 16, 2020

Secretary of State Michael Pompeo and other Trump administration officials are aware of the incident, one of the people said.

It doesn’t appear that the intrusion at HHS took any data from the systems, one of the people said.

General Paul Nakasone, who leads the National Security Agency and U.S. Cyber Command, is looking into the situation, one of the people said.