The Kucinich campaign denied involvement.
At around 9:30 a.m. a page bearing the Kucinich campaign logo appeared in place of the CBSNews.com homepage.
The screen automatically shifted to a page playing a 30-minute video called "This Is The Moment," in which the liberal congressman — aided by the likes of actor Ed Asner — outlines his philosophy.
"According to the most recent CBSnews/nytimes poll (sic), 77% of Democrats do not know enough about Dennis Kucinich. Since we can not expect the media to provide this information I decided to help them out," the hacker page read. "Please watch this video and listen to the man who has inspired me into taking this rash action."
"There are honest politicians out there, you just have to look past the bs. I suggest checking out select smart to see who really agrees with you, not simply who sounds the best," it continues. "we don't want another Florida do we people?"
The hacker page provided links to the Kucinich campaign for people who wished to contribute or volunteer.
A CBS spokeswoman said the network was looking into the matter.
A spokesman for the Kucinich campaign denied any involvement by the congressman's campaign staff.
"It cannot be that anyone in my campaign is involved in such a thing," spokesman David Swanson said. "Our campaign would never do such a thing or condone such a thing. We are not interested in taking over someone else's Web site, I can assure you."
The poll to which the hacker referred, published Thursday, revealed Kucinich running 10th in the field of 10 seeking the Democratic nomination with support from 1 percent of respondents.
When voters were asked who has the best chance of beating President Bush, Kucinich was the only candidate with 0 percent. Five percent of respondents have a favorable view of him, 8 percent had an unfavorable view, and 86 percent hadn't heard of him — making Kucinich the least-known candidate.
The poll was conducted among a nationwide random sample of 981 adults interviewed by telephone from Sept. 28 to Oct. 1, and had a margin of error of plus or minus 3 percentage points.
CBSNews.com was also hacked during the 2000 presidential campaign with anti-Bush material.