Conducting a search might seem one of the more innocuous activities you can carry out online, but start looking for adult material or clicking on sponsored links and you dramatically increase the risks of malware or a frenzy of spam, according to a new study.

Red sites typically distribute adware or make unauthorised system changes, while yellow sites use a high percentage of pop-ups or have been identified as a major source of spam. Poor email practices -- such as mailing lists which are then sold on to others -- were the most common cause for concern.

Some searches were much more dangerous than others. According to the study, adult search terms are twice as risky as non-adult phrases -- an unsurprising result, given that it's less likely that users will notice suspicious behaviour with one hand planted down their pants. Other dangerous terms include "free" and "bearshare" (which is a file sharing package, not an obscure type of pornography).

While just 3% of overall search results were rated as risky, that figure jumped to 8% for sponsored searches. Search engines rely on sponsored links to produce their revenues, but the willingness of spammers or criminals to utilise those services means they may need to become pickier about who they sign up.

"By allowing risky Web sites to buy prominent placement within search results, search engines help these sites reach -- and, potentially, harm -- unsuspecting users," the study noted.
{moscomment}