Click fraud may have dipped slightly of late, but botnets continue to be a driving force behind the activity.
According to Click Forensics, traffic from botnets accounted for 27.6 percent of all click fraud traffic in the third quarter of 2008. The company found that the amount of click fraud traffic tied to botnets has been increasing steadily in 2008, and jumped 8 percent in the first quarter of 2008 alone.
The bane of companies like Google and Yahoo, click fraud is an illegal practice that occurs when individuals click on Web site click-through advertisements such as banner ads to increase the payable number of click-throughs to the advertiser.
When botnets are providing the clicking, the problem becomes especially tricky to address, given the elusive nature of botnets themselves.
"Botnets have become in many ways a service industry," said Joe Dallatore, senior manager of the Security Intelligence Engineering group at Cisco Systems. "There's a group of people out there who built these [botnets] and have them available, and they basically go out and hire them. It's basically labor for hire to do bad things."
According to Click Forensics, the click fraud rate dropped from 16.2 percent in the second quarter to 16 percent in the third. The average third-quarter click fraud rate of pay-per-click advertisements on search engine content networks such as Google AdSense and Yahoo Publisher Network was 27.1 percent. That's down from the 27.6 percent rate reported for the second quarter and the 28.1 percent average click fraud rate reported for the third quarter of 2007.
"For the past two quarters the industry average click fraud rates [seem] to be hovering around the 16 percent level," Tom Cuthbert, president of Click Forensics, said in a statement. "Gains are being made by advertisers taking more action to proactively filter out fraud before it affects online campaigns. However, the growth in click fraud traffic from botnets continues to rise and it should be one of the top areas advertisers and the industry should monitor closely."