US Congressman Ron Paul is hot. Image spam is not.

According to Symantec's Spam Monthly Report issued at the beginning of the week, US presidential hopefuls for the 2008 election are already hot subject-line topics, with Congressman Ron Paul emerging as spammers' favorite.

Meanwhile, image spam that just a year ago was flooding -- and often fooling -- antispam filters, now only accounts for about 7% of all spam sent.

The Symantec report says spam levels continue to inch up, with unwanted messages comprising 70.5% of all e-mail last month.

October also saw the emergence of audio spam that featured MP3 files attached to unwanted e-mail messages. The attached files were labeled with pop singers' names such as Fergie and Carrie Underwood, but no music played when launched. Instead, the MP3 files are recordings of a monotone voice telling recipients to buy stock in a little-known company, giving the stock ticker symbol and directing them to read about the company in the news.

With pump-and-dump stock spam, spammers blast messages persuading people to buy a penny stock, then once the stock price goes up the spammers sells their shares at a profit.

"As antispam filters become more sophisticated, it is clear that spammers will continue to reinvent how they send spam," says the Symantec report.

Also last month, spammers launched a campaign to "click away the carbon," in attempts to appeal to recipients' greener sides. The message contains a survey that asks a series of personal questions, promising completers that a donation (the receiving organization is not specified) will be made on their behalf.

Symantec says this campaign was likely sparked by the increased media coverage of global warming lately.

Another spam highlight from October were Halloween-timed offers for downloading a dancing skeleton -- the latest hoax pulled by the ever-popularStorm malware.