The Syrian Electronic Army made headlines today for attacks on the New York Times, but Twitter may have also attracted the group's attention. In a tweet, the hackers claimed to have gained access to the DNS servers for twitter.com, along with the Huffington Post UK. Tests showed the records were indeed changed, but name servers continued to redirect to the correct IPs, and the change was most likely a result of the breach in a DNS records holding site. Multiple tests by The Verge revealed no break in the HTTPS connection to twitter.com, suggesting the IP connection was never disturbed. It therefore looks like the SEA is going after the name servers for Twitter, but hasn't directly hacked Twitter itself.
Twitter's image server, hosted separately at twimg.com, may be a different story. Multiple users on Twitter reported their backgrounds being changed to Syrian-themed images, and DNS records first found by security reporter Brian Krebs confirm that twimg.com was briefly redirecting to an SEA-affiliated site. The account also claimed to have brought down Twitter.co.uk, although the site still appears to be functional.
An official Twitter statement confirmed the hack, saying that the company's DNS provider had been compromised, and the image server had been "sporadically impacted" beginning at 4:49PM. Just before 6:30, the company regained control of the server. According to the statement, no user information was compromised. Still, many other domains may still be up for grabs. The SEA's twitter account had singled out various Twitter subdomains as targets, including Twitter services in China, Indonesia, and the United Arab Emirates, and as of press time, many of these domains still appear to be down.
Update: Business Insider has published a statement from Melbourne IT, which provides domain names in Australia. The company says that "the credentials of a Melbourne IT reseller (username and password) were used to access a reseller account on Melbourne IT’s systems." Though the reseller account has been identified, who gained access to it has not been. Melbourne IT suggests that users can "lock" their DNS settings to prevent resellers from gaining the ability to change them.