Massive attack cripples Twitter

The fabric of social networking was temporarily crippled on Thursday as Twitter and Facebook were affected by DOS (denial of service) attacks.

Twitter's 20 million or so devotees were locked out of service for a few hours while Facebook was performing slowly.

While investigations are underway, neither site has identified the culprit as yet. Most speculation is centered toward a Russian activist blogger with accounts across the impacted services.

Twitter co-founder Biz Stone wrote in a blog post, “we've worked hard to achieve technical stability. Nevertheless, today's massive, globally distributed attack was a reminder that there's still lots of work ahead.”

Twitter said it was able to restore service, but warned some users would continue to experience “degraded” service while recovery was underway.

Meanwhile, the latest Symantec’s MessageLabs report claims that the top three botnets are sending as many as 21 billion spam messages a day.

The top botnets, identified as Donbot, Cutwail and Mega-D, are responsible for distributing 15-20% of all global spam, the company said. Symantec and McAfee estimate now that spam is 90-92% of all email.

Twitter’s attack could have been hit by a botnet which work as herds of compromised computers are used to do the bidding of criminal hackers.