It was a distributed denial-of-service attack, in which a targeted server gets flooded with Internet traffic, overwhelming the system.
Bheodari said in this case, the airport was getting 29 million hits per second coming into its server.
They were coming from various international Internet Service Providers, Bheodari said. In response, the airport halted access to the server from outside the United States.
The Atlanta airport’s website wasn’t restored until about 10:17 a.m. The cyberattack did not affect flights or other airport operations, Bheodari said.
Hartsfield-Jackson is investigating the incident. The airport has been monitoring email coming in since Monday morning.
On Wednesday, Bheodari told an Atlanta City Council committee meeting, “We’re at the point where we are starting to open our server back to known entities.”