Web Sites Disrupted in Silicon Valley

Multiple Internet sites, including those run by Amazon, were temporarily disrupted for some Web users after a company that provides them directory services suffered what it called a "denial of service" attack. Neustar, which runs the UltraDNS service that helps process the connections between individual computers and Web sites, says the disruption lasted about an hour and only affected Web users in Northern California. The company said it began to notice an unusual spike in traffic on its servers at about 7:45 p.m. Eastern Time, which led to the outage. "Immediately we identified it and put mitigation measures into effect," said Allen Goldberg, a Neustar spokesman. In a denial of service attack, criminals or pranksters typically use multiple computers located around the Internet to flood a Web site with traffic, making it difficult for other users to connect. In this case, the attack caused Web users in Silicon Valley and other parts of Northern California to get either an error message or delayed response when trying to access a site that uses the directory service from UltraDNS. Goldberg said the company is still investigating the source of the attack