News 

The hacker posted 'tweets' on the micro-blogging service, masquerading as the celebrities. One post from Britney Spears' account outlined obscene details about her genitalia - a message was promptly put up on her official website declaring that her account had been hacked and apologising for any offence caused to her fans. Another, from CNN presenter Rick Sanchez's account, declared: 'i am high on crack right now might not be coming to work today'.

Fox News was also targeted, as the hacker posted a tweet from the company's Twitter account claiming one of their presenters was gay. Barack Obama was another victim, offering those who completed a survey about what they thought of Obama a $500 gas card as a reward.

Meanwhile, technophile Stephen Fry said he was tricked into clicking on a scam message. He later posted: 'Hope I haven't been phished for all my details. Clicked on scam URL before I realised what it

ADVERTISEMENT

was. Eeek.'

Twitter responded by suspending the 33 accounts, and restricting the use of some of its support tools. "We considered this a very serious breach of security and immediately took the support tools offline. We'll put them back only when they're safe and secure," said Twitter co-founder Biz Stone on the Twitter blog,

According to David Emm from the global research and analysis team at security provider Kaspersky Lab, the attck is the latest indication that in 2009 cybercrimals will consider such social networking sites as viable medium for spreading and profiting from crimeware.

"Initial signs that this trend would become a reality were raised in May 2008 when the BBC identified how it was possible for Facebook users to have their personal details stolen via a malicious program masquerading as a harmless application that users add to their profile. Several months later Kaspersky Lab detected two variants of the now famous Koobface worm, Networm.Win32.Koobface.a. and Networm.Win32.Koobface.b, which were attacking the social networking websites MySpace and Facebook respectively, transforming victim machines into zombie computers to form botnets.

"Social networking sites are easy prey for cyber criminals. On the one hand, users are very trusting of these sites, so they lower their guard. On the other hand, vulnerabilities in these sites are often left open for significant periods of time, making it easy for hackers to take full advantage of security loopholes."