Religious and idealogical websites have triple the amount of malware than porn sites, according to Symantec.

It's a well-known Internet fact that many an adult website is riddled with harmful viruses or malware, right? Maybe not.

Tucked within was this interesting nugget: religious and ideological websites have "triple the average number of threats per infected site than adult/pornographic sites."

Why? Symantec suggested a very practical reason.

"We hypothesize that this is because pornographic website owners already make money from the Internet and, as a result, have a vested interest in keeping their sites malware-free  it's not good for repeat business," the company said.

Symantec didn't go into detail about what it considered to be a religious or ideological website. Overall, the company identified 403 million unique malware variants in 2011, while the number of Web attacks that were blocked on a daily basis jumped 36 percent.

On its list of most dangerous website categories, blogs/Web communications landed at No. 1 with 19.8 percent being infected. That was followed by hosting/personal hosted sites (15.6 percent), business/economy (10 percent), shopping (7.7 percent), and education/reference (6.9 percent). Porn landed at No. 10 with 2.4 percent.

Evidence suggests that scammers are getting a bit more sophisticated, too. "Badly-spelled, implausible email has been replaced by techniques such as 'clickjacking' or 'likejacking' where a user visits a website to watch a tempting video and the attackers use that click to post a comment to all the user's friends on Facebook, thereby enticing them to click on the same malicious link," Symantec said.