Spam surged to 72% of overall e-mail traffic monitored by Symantec in November, the highest percentage for any month this year, according to Symantec’s monthly “State of Spam Report.”

Spam volumes more typically hover in the 50% to 60% range. Doug Bowers, a senior director at Symantec, chalked up the November surge to a decisive effort by spammers to increase their capacity to send more e-mail using tactics such as the Storm worm. “The fact that spam volume continued to increase and stayed up seems to signal they were having some success,” Bowers says.

Symantec, which gathers data by monitoring 450 million in-boxes worldwide (compare products), also says November saw the first traces of Olympics-related spam due to the upcoming 2008 Olympics in Beijing. In addition, there was a huge e-mail harvesting campaign in which Symantec blocked more than 35 million blank-message e-mails.

In niche categories observed in November, spammers were disguising a virus-hosting site in spam e-mails by exploiting international public interest in the case of the missing British child, Madeleine McCann. Another odd sighting, Symantec notes, was spam that uses a “funny .GIF that shows a snowball hurtling at you through your computer.” Spammers are also said to be taking advantage of the season to market free gift cards for well-known companies.