Hackers hit the heart of the Internet yesterday when they launched an attack on three of the 13 root servers that are responsible for directing all web traffic. The computers were disabled for 12 hours before resuming routine operations.

The hackers hit the UltraDNS company, which directs traffic to websites containing the .info and.org suffixes. The attacks went unnoticed for several hours because legitimate traffic remained unaffected.

UltraDNS chief executive Ben Petro talked to ComputerWire about these unusually powerful attacks and said that the company's network was severely tested. "We have not seen an attack act in this fashion with this methodology before," said Petro. "We are at risk, e-commerce is at risk and to an extent the global economy is at risk."

He added that the hackers sent two million packets per second were flooded into UltraDNS' servers.

Commenting on the incident John Crain, chief technical officer for the Internet Corporation for Assigned Names and Numbers (ICANN), said that this was the most dangerous attack since October 2002 when hackers had targeted all 13 root servers.