'Zombie' PCs caused Web outage, Akamai says - News - ZDNet

'Zombie' PCs caused Web outage, Akamai says - News - ZDNet:
"The attack that blacked out Google, Yahoo and other major Web sites earlier this week involved the use of a 'bot net'--a large network of zombified home PCs--Internet infrastructure provider Akamai Technologies said Wednesday.

The attack, which blocked nearly all access to Apple Computer, Google, Microsoft and Yahoo's Web sites for two hours on Tuesday, took aim at the key domain name system (DNS) servers run by Akamai. These servers translate word-based URLs, such as www.microsoft.com, into the numerical addresses used by the Internet. Using compromised home computers, the attackers sent a flood of data to the DNS servers, preventing them from providing that translation and effectively shutting surfers out of the four companies' pages, according to Akamai.

The deluge of data that hit the infrastructure provider was 'so large that it (couldn't have) come from a couple of servers,' said Tom Leighton, chief scientist and co-founder of Akamai. 'Working with our network partners, we were able to identify a bot network that appeared to be operating and managed to shut it down, which resulted in stopping the attack.' "

Bot networks are collections of computers that have been compromised by software specifically designed to create a network of systems for attack. A bot--also known as remote-access Trojan horse program, or RAT--seeks out and places itself on vulnerable PCs. It then runs silently in the background, letting an attacker send commands to the system while its owner works, oblivious. The computers are essentially turned into zombies, controllable from afar.…

http://zdnet.com.com/2100-1105_2-5236403.html