Twitter was down for more than an hour early Thursday morning, before the eponymous California firm got it back online.
‘The continuing denial of service attack is being mitigated although there is still degraded service for some folks while we recover completely,’ Twitter co-founder Biz Stone said in an official company blog.
‘Twitter has been working closely with other companies and services affected by what appears to be a single, massively coordinated attack. As to the motivation behind this event, we prefer not to speculate.’
By late Thursday afternoon, Twitter said that service was improving but still sporadic with some people ‘unable to post or follow from the website.’
Facebook was ‘degraded’ by an early-morning distributed-denial-of-service (DDoS) attack on the Palo Alto, California-based Internet star’s website, said Facebook spokeswoman Brandee Barker.
‘No user data was at risk and we have restored full access to the site for most users,’ Barker said. ‘We’re continuing to monitor the situation.’
Twitter and Facebook have teamed with US Internet powerhouse Google to investigate the attacks.
Cyber attacks were launched on Google websites, but the firm deflected the assaults.
‘Google systems prevented substantive impact to our services,’ said company spokesman Nate Tyler.
‘We are aware that a handful of non-Google sites were impacted by a DOS attack this morning, and are in contact with some affected companies to help investigate this attack.’
Hackers evidently employed classic DDoS attacks in which legions of zombie computers, machines infected with viruses, are commanded to simultaneously visit a website.
Such massive onslaught of demand can overwhelm website computer servers, slowing service or knocking it offline.
‘Ten years ago we saw the first DDoS attacks take down some of the world’s largest web sites,’ said Cisco chief security researcher Patrick Peterson.
‘The irony here is that botnets, infected criminally-controlled consumer PCs, are the problem. Many of today’s tweetless are part of the attack if their PC has been infected due to poor security.’
A DDoS attack hit Twitter about 6:00 am local time (1200 GMT) and caused the service to go offline temporarily.
Access to the website continued to be slow, with some aspiring users getting messages telling them that connections had ‘timed out’ because Twitter computers were taking too long to respond.
The attack was the lead topic of conversation at Twitter, as people connected to the service to comment about being unable to connect to the service.
Twitter user Benjamin Hobbs fired off a message saying he ‘wishes the Denial-of-Service idiots would get a life and leave Twitter alone.’
While an everyday chatting tool for many, Twitter has become a weapon used by dissidents to circumvent censorship in places where freedom of speech is suppressed.