Hillary Clinton is the most popular candidate online with 1,080 domain names registered in her name including sites such as Clintonsucks.org.
Barack Obama trails his Democratic rival with 635 registered domain names, including Thebarackobamasong.com which features a tune written and performed by supporter Alan Burrell.
Republican candidate John McCain lags well behind his two rivals with just 269 dedicated domain names registered in his name.
They are largely unflattering domain names such as Stopjohnmccain2008.com and Mccainsucks.com.
"The US presidential race is attracting rolling news coverage and all of the candidates have invested significantly in engaging their electorates online, but it is very difficult to stop negative websites being created," said Jonathan Robinson, chief operating officer for NetNames.
"In the meantime, cyber-squatters are cashing in by registering domain names relevant to the presidential candidates to lead unsuspecting people to pages full of pay-per-click advertising."
While a significant number of domain names lead to support or hate sites, a large proportion lead straight to ad-revenue sites where cyber-squatters are making money out of people looking for official information on the candidates.
One cyber-squatter from California even tried to sell the Ihatebarackobama.com and Ihatehilaryclinton.com domains for US$1,299 immediately after registering them.