Twitter’s website went offline for about an hour Thursday, with many tweeters redirected to a defacement page boasting “This site has been hacked by Iranian Cyber Army.”

Twitter acknowledged the 10 p.m. takeover, one in a series of security lapses to hit the popular microblogging service. Twitter said its DNS records “were temporarily compromised.”

Tom Daly, chief technology officer at Dyn, a New Hampshire-based DNS company that services Twitter, said somebody using a “set of valid Twitter credentials” redirected the site.

“From our perspective, it was a perfectly valid username-and-password combination that was logged in with,” Daily said in a telephone interview. “The only credentials that were compromised were Twitter’s.”

Daly declined to identify the name of the Twitter employee whose account was breached. Twitter did not immediately respond for comment.

Among other statements, the unknown group wrote this on the redirected site:

U.S.A. Think They Controlling And Managing Internet By Their Access, But They Don’t, We Control And Manage Internet By Our Power, So Do Not Try To Stimulation Iranian Peoples To …

The hijacking came nearly six months after the microblogging service, with some 20 million users, helped Iranian protesters plan demonstrations against presidential election results. In a bid to help the protesters, the Obama administration convinced Twitter to delay scheduled June maintenance that would have temporarily taken Twitter offline.

See Also:

• Twitter Suspends Researcher Over Security Warning
• Weak Password Brings ‘Happiness’ to Twitter Hacker
• Twitter Breached Again
• Trick or Tweet? Malware Abundant in Twitter URLs
• Fed’s Search of Twittering Anarchist Upheld
• Britney, Obama Twitter Feeds Hijacked Following Phishing Attack