A “bazooka” cyberattack described as the most powerful ever seen has slowed traffic on the Internet, security experts said on Wednesday, raising fresh concerns over online security.
The attacks targeted Spamhaus, a Geneva-based volunteer group that publishes spam blacklists used by networks to filter out unwanted e-mail, and led to cyberspace congestion that may have affected the Internet overall, according to Matthew Prince of the US security firm CloudFlare.
The attacks began last week, according to Spamhaus, after it placed on its blacklist the Dutch-based Web hosting site Cyberbunker, which claimed it was unfairly labeled as a haven for cybercrime and spam.
The origin of the attacks has not yet been identified, but a BBC report said Spamhaus alleged that Cyberbunker, in cooperation with “criminal gangs” from Eastern Europe and Russia, was behind the attack.
The New York Times quoted Sven Olaf Kamphuis, who claimed to be a spokesman for the attackers, as saying that Cyberbunker was retaliating against Spamhaus for “abusing their influence.”
However, Kamphuis told the Russian news site RT that Cyberbunker was just one of several Web firms involved, protesting what he called Spamhaus’ bullying tactics.
“Spamhaus have pissed off a whole lot of people over the past few years by blackmailing ISPs [Internet service providers] and carriers into disconnecting clients without court orders or legal process whatsoever,” he said.
“At this moment, we are not even conducting any attacks... it’s now other people attacking them,” he said.
CloudFlare, which was called for assistance by Spamhaus, said the attackers changed tactics after the first layer of protection was implemented last week.
“Rather than attacking our customers directly, they started going after the network providers CloudFlare uses for bandwidth,” Prince said.
“Once the attackers realized they couldn’t knock CloudFlare itself offline ... they went after our direct peers,” he said.
Prince said the so-called distributed denial of service attack (DDoS), which essentially bombards sites with traffic in an effort to disrupt, was “one of the largest ever reported.”
Over the last few days, he added: “We’ve 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 unrelated 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,” Prince said in a blog post called “The DDoS That Almost Broke the Internet.”
Prince said these attacks used tactics different than the “botnets” — these came from so-called “open resolvers” that “are typically running on big servers with fat pipes.”
“They are like bazookas and the events of the last week have shown the damage they can cause,” he said. “What’s troubling is that, compared with what is possible, this attack may prove to be relatively modest.”
A spokesman for the network security firm Akamai said that based on the published data, “the attack was likely the largest publicly acknowledged attack on record.”
“The cyberattack is certainly very large,” added Johannes Ullrich of the US-based SANS Technology Institute, saying it was “a factor of 10 larger than similar attacks in the recent past.”