Twitter and The New York Times were hit with cyber attacks, with credit quickly claimed by a group backing embattled Syrian strongman Bashar Al-Assad.
The Times site remained out of service early Wednesday following the attacks that began Tuesday.
The Syrian Electronic Army (SEA), ironically, used Twitter to tout its efforts to take down the globally popular one-to-many messaging service and the Times news website.
"Media is going down," a message at the SEA Twitter account proclaimed. "Twitter, are you ready?"
The cyber attack was evidently aimed at the Domain Name System that that acts as a directory of sorts for routing online traffic to website addresses.
Hackers can hijack web traffic by altering DNS address information to send site visitors to websites of their choosing.
An Australian domain registration service appeared to have been hit in the attack.
"Our DNS provider experienced an issue in which it appears DNS records for various organizations were modified, including one of Twitter's domains used for image serving, twimg.com," Twitter said in a post at its status blog.
"Viewing of images and photos was sporadically impacted," the San Francisco-based company's message explained.
"No Twitter user information was affected by this incident."
The trouble was resolved within two hours, according to Twitter.
The New York Times said that its website went down Tuesday due to a "malicious external attack."
Times spokeswoman Eileen Murphy also made the announcement on Twitter, two weeks after the site went offline due to what the daily said was an internal server problem.
Her full tweet said: "re: http://nytimes.com - initial assessment - issue is most likely result of malicious external attack. working to fix."
The newspaper's main Twitter account said shortly after 2000 GMT that the website "is experiencing technical difficulties" but that news was still being published via Twitter and other links.
Matt Johansen of WhiteHat Security said in a tweet that the technical aspects of the website during the outage were "pointing to Syrian Electronic Army."
The SEA has claimed responsibility in the past for cyber attacks on other major news outlets.
The Washington Post website was hacked this month in an attack blamed on the SEA.
The Times said in January that hackers stole its corporate passwords and accessed the personal computers of 53 employees after the newspaper published a report on the family fortune of China's Premier Wen Jiabao.