Internet slows down on largest cyber attacks yet

Security experts say the internet might have been slowed by one of the largest cyber attacks ever seen, which targetted a European group that patrolled the web for spam.

Spamhaus, a Geneva-based volunteer group that publishes spam blacklists came under ferocious attack. Spam blacklists are used by networks to filter out unwanted email. According to Matthew Prince of the US security firm CloudFlare, the attacks may have affected the overall internet.

According to Spamhaus, the attacks started last week, after it placed on its blacklist the Dutch-based web hosting site Cyberbunker, which claimed it had been unfairly labelled as a haven for cybercrime and spam.

Though the origin of the attacks had not been traced, according to some experts, Cyberbunker, possibly in coordination with Eastern European cyber-criminals might have been responsible.

According to CloudFlare, which was called for assistance by Spamhaus, the attackers changed tactics after implementation of the first layer of protection last week.

Prince said, rather than attacking its customers directly, they went after the network providers CloudFlare used for bandwidth.

According to Prince the so-called denial of service attack, which essentially bombarded sites with traffic in an effort to disrupt, was one of the largest ever reported.

Over the last few days, he added, the company had seen congestion across several major Tier 1 (networks), primarily in Europe where most of the attacks were concentrated, that would have affected hundreds of millions of people even as they surfed sites not related to Spamhaus or CloudFlare.

"If the Internet felt a bit more sluggish for you over the last few days in Europe, this may be part of the reason why," he said in a blog post.

The attack was powered by ''open recursive resolvers,'' which allow attackers to turn modest attacks into overwhelming floods of traffic.