Online spat over spam jams whole Internet

A Dutch company's retaliation against group fighting spam caused congestion and jamming worldwide

Published March 27, 2013 12:39PM (EDT)


A spat between a spam-fighting group and a large Dutch Web hosting service led to the jamming of crucial online infrastructure, causing temporary congestion for millions of Internet users worldwide.

Spamhaus, a group that helps Internet users avoid spam by adding sites believed responsible for sending out such content to a blacklist, added Dutch company Cyberbunker -- a (sometimes controversial) hosting service -- to its list. Cyberbunker's supporters hit back with a vengeance, with cyberattackers carrying out strikes that exploited the Internet’s core infrastructure, called the Domain Name System, or DNS. As a result, noted the New York Times, "Millions of ordinary Internet users have experienced delays in services like Netflix or could not reach a particular Web site for a short time." The Times reported that the "attacks are becoming increasingly powerful, and computer security experts worry that if they continue to escalate people may not be able to reach basic Internet services, like e-mail and online banking."

Via the Times:

In the past, blacklisted sites have retaliated against Spamhaus with denial-of-service attacks, in which they flood Spamhaus with traffic requests from personal computers until its servers become unreachable. But in recent weeks, the attackers hit back with a far more powerful strike that exploited the Internet’s core infrastructure, called the Domain Name System, or DNS.

That system functions like a telephone switchboard for the Internet. It translates the names of Web sites like or into a string of numbers that the Internet’s underlying technology can understand. Millions of computer servers around the world perform the actual translation.

In the latest incident, attackers sent messages, masquerading as ones coming from Spamhaus, to those machines, which were then amplified drastically by the servers, causing torrents of data to be aimed back at the Spamhaus computers.

When Spamhaus requested aid from Cloudflare, the attackers began to focus their digital ire on the companies that provide data connections for both Spamhaus and Cloudflare.

Questioned about the attacks, Sven Olaf Kamphuis, an Internet activist who said he was a spokesman for the attackers, said in an online message that, “We are aware that this is one of the largest DDoS attacks the world had publicly seen.” Mr. Kamphuis said Cyberbunker was retaliating against Spamhaus for “abusing their influence.”

By Natasha Lennard

Natasha Lennard is an assistant news editor at Salon, covering non-electoral politics, general news and rabble-rousing. Follow her on Twitter @natashalennard, email

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Cyberbunker Ddos Domain Name System Internet Spam