"Cyber-criminals are always on the lookout for new tricks, but they are also sticking with an oldie-but-goodie—abusing search engine results. According to security pros, there has been a significant increase in the tactic since January. On March 10, officials at Symantec noted attackers were using sponsored search results on Yahoo to lure Web surfers to malicious site that promoted a fake anti-virus product called "Antivirus & Security."
The search result purported to be a link to the latest version of AVG Technologies’ anti-virus software. In truth, however, it led to Antivirus-2009-new.com and Antivirus-pro-download.com, where users were asked to make a payment to buy a membership to get the rogue AV application." – Content courtesy of Abuse of Google, Yahoo Search by Cyber-crooks Is Rising