ClickForensics, one of the top traffic quality management companies, reports that click fraud performed with the use of botnets is on the rise. In the third quarter of this year this type of activity has registered a 15 percent rise compared to the same period in 2008.

ClickForensics compiled and analyzed the data from its specialized system that monitors fraud activity associated with Cost Per Click (CPC) advertising campaigns. According to the company, the collected data spans more than 300 advertising networks, including the top search engines.

Compared to the previous year, the click fraud average rate was down by almost two percent during Q3 2009. Fraudulent clicks accounted for around 14% of the total number of hits, which is however an increase over Q2, when they represented 12.7%.

One of the most worrying problems identified is the use of botnets to automate click fraud. This type of activity represented 42.6% of the total click fraud rate. "This was a significant rise - more than doubling in the past two years and up from the 27.5 percent reported for the same quarter last year," the ClickForensics report notes.

This unusual increase is likely the result of new specialized malware, such as the Bahama botnet, which was identified back in September and has been held responsible for the malvertizement incident on the New York Times website. This threat has impressed researchers through its complexity and the new techniques used, such as hijacking search queries intermittently in order to avoid drawing suspicion.

Another interesting click fraud malware discovered in August by Trend Micro analysts, functioned as a Firefox rogue extension. This suggests that click fraud is starting to become a profitable business for cybercriminals if performed on a large scale and targeting all browsers.

"Botnets perpetrating click fraud and other online schemes continue to grow in number and sophistication. Advertisers and ad providers need to be especially vigilant about such activity as we enter the competitive search marketing holiday season," Paul Pellman, CEO of Click Forensics, concludes.