A pro-Russian hacker group is taking credit for temporarily taking down several U.S. airport websites on Monday, though there appeared to be no impact on flight operations.
The attacks claimed by Killnet impacted the websites for Los Angeles International, Chicago O'Hare, and Hartsfield-Jackson International in Atlanta, among others.
The group posted a list of airports on Telegram, urging hackers to participate in what's known as a DDoS attack — a distributed denial-of-service caused when a computer network is flooded by simultaneous data transmissions.
The group's call to action included airports across the country, including Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, and Missouri.
It was not immediately clear how many of the airports were actually hit and whether all victims' sites suffered any disruptions.
In a statement, LAX officials told NPR that FlyLAX.com was partially disrupted early Monday morning.
"The service interruption was limited to portions of the public facing FlyLAX.com website only. No internal airport systems were compromised and there were no operational disruptions," a spokeswoman said in an emailed statement.
She added that the airport's information technology team has restored all services and is investigating the cause. Officials have also notified the FBI and the Transportation Security Administration.
By about 1 p.m. in Atlanta, authorities said ATL.com was "up and running after an incident early this morning that made it inaccessible to the public." But people on Twitter continued to complain about parts of the site being inaccessible for several hours after the announcement had been made.
Atlanta airport officials said no airport operations had been impacted.
In an earlier post on Monday, Killnet noted other vulnerable U.S. sites that could succumb to similar DDoS strikes, include sea terminals and logistics facilities, weather monitoring centers, health care systems, subway systems, and exchanges and online trading systems.
The group congratulated a handful of teams they claimed helped push the sites offline, writing, "Who is participated in the liquidation of the United States of America, Do not stop!!"
The attacks come on the heels of another spate of cyberattacks allegedly launched by the group last week. In that instance, the group has taken credit for rallying hackers to down state government sites.
Both campaigns appear to have been prompted by anti-U.S. sentiment for the country's involvement in the ongoing war in Ukraine, as Russian President Vladimir Putin presses on with the invasion despite severe economic sanctions.