Al Jazeera's main website was also defaced at one point, according to a captured by Zone-H.org, which tracks website vandalism. A group calling itself Al-Rashedon claimed responsibility, displaying a Syrian flag and large red stamp reading "Hack."

Babar Mustafa, a senior software engineer with Al Jazeera, that "DNS [Domain Name System] poisoning issues are being resolved by our provider."

ISPs often provide DNS services to their customers. Tampering with DNS settings can be particularly harmful, since users can be redirected to a fake website even though a correct domain name has been typed into a web browser. The type of attack is know as DNS "poisoning."

The DNS issue caused Al Jazeera's websites to be available in some parts of the world but not others. Mustafa that people visit "www.aljazeera.com" rather than just "aljazeera.com," although the variation did not work from Australia on Wednesday morning. Another domain, "www.aljazeerasport.net," was also offline.

Political unrest in the Middle East had caused increased activity from hackers motivated by political causes who target high-profile websites in order to embarrass entities that the activists dislike. In March 2003, Al Jazeera was hit with a distributed denial-of-service attack following its broadcast of photos of U.S. soldiers who had been captured by Iraqi forces.