Updated A denial of service attack against Wikileaks that brought the whistleblower site to its knees on Sunday night, in the run up to its publication of classified State Department documents, may turn out to be the work of a lone hacker.

The attack, which rendered the site inaccessible for several hours, might be blamed on an application level assault targeting a vulnerability in Wikileak's Apache web server, according to internet reports.

A patriot-hacker called The Jester has previously used the XerXeS attack tool to attack jihadist sites. Now, if rumours are to be believed this tool was turned against Wikileaks on Sunday, making the site unavailable at a critical time.

Hundreds of thousands of US diplomatic cables were still published by The Guardian, with extracts run by other high-profile media publications, so the attack failed to block access to the diplomatically and politically embarrassing information, always an unrealistic goal.

"We are currently under a mass distributed denial of service attic," Wikileaks said on Sunday night, via updates to its Twitter feed. "El Pais, Le Monde, Speigel, Guardian & NYT will publish many US embassy cables tonight, even if WikiLeaks goes down," it added.

Rather than a purely conventional packet flood, it seems probable that the site was also hit by the XerXeS tool. A video showing how the tool works and an interview with the Jester (@th3j35t3r) can be found via Infosec Island here.

The Jester claimed responsibility for an attack on Wikileaks via a Twitter update on Sunday: "www.wikileaks.org - TANGO DOWN - for attempting to endanger the lives of our troops, 'other assets' & foreign relations," he said.

The Obama administration strongly condemned the leak of the diplomatic cables in similar terms arguing that the release puts lives at risk, damages US relations with its allies and undermines counterterrorism operations.

Claims by the Jester could, of course, just be hacker braggadocio and it may turn out that a more significant conventional packet flood attack was actually the main culprit in bringing Wikileaks to its knees. Analysis of the attack remains far from complete.

The release of the diplomatic cables on Sunday was Wikileaks's biggest release to date, and follows the controversial release of the Iraqi War Logs.

In related news, Wikileaks websites have been moving around hosting providers a great deal over the last month or so, most recently in response to the denial of service attack launched against the main site on Sunday. The DNS configurations over the warless.wikileaks.org site were changed over the previous week so that the site is served solely by French hosting provider Octopuce.

But after the denial of service attacks WikiLeaks moved their IP address back to Amazon Ireland. The CableGate site is on the same Amazon US server systems that previously hosted the Iraqi War logs, technology blogger Alex Norcliffe reports. ®