NEW YORK (Reuters) - Computer hackers briefly hijacked Twitter.com on Thursday, redirecting its users to a website where a group calling itself "Iranian Cyber Army" claimed responsibility for the disruption.
It was unlikely that the Iranian government itself was involved despite its dislike of social networking sites and years of discord with the United States over its nuclear program, experts said.
Twitter was apparently disrupted for about two hours by the group, which replaced the Twitter home page with a headline reading "This site has been hacked by Iranian Cyber Army" and an anti-American message.
A screen shot posted in a number of places on the Web, including TechCrunch, shows the message written in red, set above a green flag. An email sent to the address on the redirected Web page was returned.
Twitter, on its official blog, also said some of its records had been "temporarily compromised" but the problem had been fixed and it would investigate.
Security experts said it was the first time hackers have succeeded in hijacking a major social-networking website, but also added it was unlikely that the attackers gained access to the database that contains user passwords.
Instead, they believe the hackers obtained credentials to change the servers where users are directed when they enter Twitter's Web address.
Privately held Dyn Inc is responsible for maintaining those records. Company officials declined comment.
Twitter, which allows people to broadcast 140-character text messages over the Web, has previously found itself caught up in Iranian politics. In June, it became a key form of communication in Iran amid the protests and clampdown that followed the country's disputed elections.
The U.S. State Department urged Twitter to delay maintenance that would have interrupted the site's service during the peak of the demonstrations.
As for Thursday's attack, a source close to Homeland Security said that the Iranian government was likely not involved because of the unsophisticated nature of the work.
Still, James Lewis, a cybersecurity effort with the think tank Center for Strategic and International Studies, said the attack may have come from a group supportive of the government.
"This is ham-handed so it's probably not the Iranian government. It could be sympathizers," said Lewis, who added that the government would have been more likely to hack Twitter during protests or other upheaval when the site was being used by dissidents.
(Reporting by Paul Thomasch in New York, Diane Bartz in Washington, Jim Finkle in Boston, and A.Ananthalakshmi in Bangalore; Editing by Lisa Von Ahn, Steve Orlofsky, Gary Hill)
