How the world’s largest cyberattack slows down your Internet use

Normally you can blame slow-loading websites on a sluggish Internet connection speed, but this week, it could be the result of a very large global cyberattack.

The European nonprofit spam filtering company Spamhaus reportedly is fending off DDoS, or distributed denial-of-service attacks, that briefly took the site offline (it is now back up) and is causing widespread congestion on the Web.

Spamhaus creates blacklists of servers that spammers use to send messages for e-mail providers, so providers can then filter spam for their users. The company had recently added the Dutch website hosting company CyberBunker and its ISP, A2B Internet, to its list.

The attack began March 18. Spamhaus was overwhelmed with traffic in a clear DDoS attack, and turned to the security team at CloudFlare to get the site back up and running. CloudFlare disclosed the technical details of the attack on March 20.

[Read: The DDoS that almost broke the Internet]

It's not over yet.

The attackers are still flooding Spamhaus with traffic, the scale of which has reached 300Gbps. A severe attack that could take down a normal website is 50Gbps. And because traffic is coming from servers all over the world, it has been difficult to slow down or stop the attack without turning off those servers and effectively bringing the Internet to a halt.

No end in sight

Though it’s difficult to pinpoint who is responsible for the large-scale attack, CyberBunker’s Sven Olaf Kamphuis is reportedly taking credit, according to the BBC and New York Times.

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CyberBunker has an anything-goes philosophy when it comes to web-hosting, refusing only child pornography and terrorism-related material.

CyberBunker’s site details the conflict with Spamhouse, claiming that it was “Chinese-based customers peddling replicas and torrent tracker services” that garnered the spam filter’s ire, not anything more nefarious.

This isn’t the first time CyberBunker has come under fire; its site also recounts the story of a SWAT team invasion of its Cold War-era nuclear bunker headquarters.

According to security firm Kaspersky Lab, attacks of this kind are escalating in scale and frequency, which is bad news for Web-surfers.

“The data flow generated by such an attack may affect intermediate network nodes when it passes them, thus impeding operations of normal Web services that have no relation to Spamhaus or CyberBunker,” Kaspersky’s global research and analysis team said in a statement.

“Therefore, such DDoS attacks may affect regular users as well, with network slowdown or total unavailability of certain Web resources being typical symptoms. There may be further disruptions on a larger scale as the attack escalates.”

Updated 3/28/2013 with the removal of information involving Netflix, whose service was not affected by the attack.

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