Websites that publish controversial material are facing a barrage of politically-motivated computer attacks, say Harvard University researchers.
The researchers, who launched the survey after hearing complaints from website owners, identified almost 300 attempts to silence independent media and human rights websites over the past year.
The researchers, who launched the survey after hearing complaints from website owners, identified almost 300 attempts to silence independent media and human rights websites over the past year.
"There is almost always a political component to these attacks," says Jillian York, one of the report's authors.
The researchers focused on distributed denial of service (DDoS) attacks, the technique that temporarily downed the Wikileaks website last month. DDoS attackers aim a flood of signals at a target website until the site, or the network that connects it to the internet, collapses under the strain of the incoming data.
Hundreds of attacks
The Wikileaks attacks were described at the time as a new and dangerous attempt to limit free speech. They are anything but new, according to the report. York and colleagues identified 140 attacks aimed at 280 media and human rights sites over the 12-month period ending in August of this year. They also surveyed the administrators of 45 media and human rights sites; 28 said they had been the target of a DDoS attack in the past year.
Targets include the protest site bauxitevietnam.info, which campaigns against a Chinese-backed project to mine bauxite in an environmentally sensitive part of Vietnam. It went down last January after tens of thousands of Vietnamese computer users were fooled into downloading software that aimed a flood of signals at the site.
Large scale problem
The Harvard team itself has been the victim of an attack. Their server also hosts the site of the Citizen Media Law Project, which supports online and citizen media. The site went down for two hours and remained unstable for a day at the end of August after being targeted by a network of 500 computers, says Hal Roberts, who also worked on the report. As with almost all other DDoS incidents, it is impossible to know who coordinated the attack.
The fact that attackers were able to force the law site offline illustrates the scale of the problem, adds Roberts. The site's server is overseen by two skilled administrators. For less well resourced sites, some of which are set up by volunteers using free-to-use software, the downtime can run to day or weeks. He and York suggest that media and human rights organisations run mirror sites at large blogging platforms, such as Blogger, which can withstand the traffic generated by most DDoS attacks.
Weapon or protest tool?
The Wikileaks attacks brought DDoS to the attention of the public, but security experts have long been aware of the problem. Gunter Ollmann of Damballa, a computer security firm based in Atlanta, Georgia, has blogged extensively on DDoS attacks and notes that as well as being used to silence critics, they are often used as a form of protest. Some commentators have described the attacks on PayPal and Mastercard, which took place after the companies severed links with Wikileaks, as virtual "sit-ins".
"DDoS tools and tactics are unfortunately a very common tactic, whether someone is trying to knock off the opposition within an online game, such as World of Warcraft, or extorting money from gambling sites in the lead up to a major sporting event," he says.
