Hackers launched an attack Tuesday on at least three of the 13 root systems dedicated to DNS, or domain name system, that help to resolve alphanumeric domain names to their specific IP addresses.

“There was what appears to be some form of attack during the night hours here in California and into the morning,” said John Crain, chief technical officer for ICANN.

The attacks lasted for as long as 12 hours, causing several DNS servers to slow to a crawl from the bombardment. But thanks to the resiliency built into the Internet’s design, most users continued on about their business unaffected during the attack.

“It is an unusual large amount of traffic that is hitting DNS servers. We see large attacks on a regular basis, but this hit quite a few servers, so it was fairly large,” said Crain. “It was extraordinary in the fact that it happened to multiple systems at once, but this is not affecting Internet users.”

“The main thing is that there was very little impact on the general public, the servers were able to hold up against the attacks,” said Zully Ramzan, a researcher at Symantec Security Response, in a CNET story. “The Internet in general was designed to even withstand a nuclear attack.”

Reports from the AP say that experts have traced a significant amount of the rogue data to South Korea, which could be where the attacks originated. Representatives from ICANN and Symantec still believe that much investigation needs to be done before determining the true cause of the attacks.

“I don't think anybody has the full picture,” Crain said. “We're looking at the data.”