Events | 2009.08.06
Twitter site disabled after virus attack
• Virus-infected PCs target social networking service
• Facebook and LiveJournal also experience problems
A malicious attack caused by thousands of remote-controlled virus-infected PCs disabled Twitter for two hours today.
Other large sites, including Facebook and the blogging site LiveJournal, also seemed to have problems at the same time — around 3pm.
Twitter\'s service was restored, but the company said it was "continuing to defend against and recover from this attack".
The site was not forced completely offline: its search pages still worked. However, people could not send or receive new tweets, or access the site directly.
The disruption will have been felt most keenly in London, which Twitter\'s co-founder and chief executive Evan Williams revealed this week has more Twitter users than any other city in the world.
The company\'s status blog said: "We are defending against a denial-of-service attack." Once the service was resumed, co-founder Biz Stone commented wryly that "we had a lot of things we\'d rather be doing this morning. Defending against a DoS wasn\'t one of them".
Facebook said it was "looking into" possible problems with its site, which also appeared to be intermittently down.
Denial-of-service attacks occur when the controllers of "botnets" consisting of many thousands of virus-compromised Windows PCs target a site. In the past, banking, gambling, news sites and Google have been the target of such attacks.
The attacks use the electronic equivalent of ringing the site\'s doorbell and running away: the targeted site\'s server wastes its resources answering the call. In a typical attack, there may be millions of such fake approaches.
The aim is often to blackmail the site: sometimes the owners are told that unless they make a payment, the attacks will continue. Gambling sites have often suffered attacks before major sports events, and been warned that more will follow unless they pay protection money.
It is not clear whether that was the aim of the attack on Twitter.
Tracking down the source of such an attack can be extremely difficult because the individual computers in the botnet used to generate the attack are controlled remotely.
Twitter has become one of the fastest-growing social networking sites in the world. The UK is believed to have about 2.4m Twitter users, according to an Ofcom report, although its explosive growth may mean the figure is out of date.
Denial-of-service attacks have become relatively commonplace online, but this is believed to be the first time that Twitter has been targeted. As companies get larger and more geographically distributed, they can handle such attacks because their servers are remote from each other. Twitter is still comparatively small, with most of its resources in the US.
For more information, please visit
http://www.guardian.co.uk/technology/200[...]ook-livejournal-attack-hackers
