Botnets aren't slowing down. That is the indication from the latest Click Forensics report in which researchers found that click fraud by botnets increased 10% in Q3 2008. Currently, about 27% of click fraud is attributed to botnets.

Overall, the click fraud rate is holding steady at about 16% for the quarter; that is a slight decrease (roughly 0.2%) from Q2 2008 as well as year over year.

"For the past two quarters the industry average click fraud rates seems to be hovering around the 16 percent level," said Tom Cuthbert, president of Click Forensics. "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."

Other interesting notes from the report include a 27.1% click fraud rate for PPC ads appearing on search engine content networks such as Google AdSense or Yahoo Publisher Network. Researchers also found a 2% overall click fraud increase by botnets.

Outside of the United States, click fraud originates from Russia (4.9%), France (4.8%) and the UK (3.5%) most often.

Tags: adsense, advertisers, botnets, campaigns, click forensics, content networks, cuthbert, france 4, fraud rate, google, network researchers, q2, q3, quarters, russia, search engine, traffic, united states, yahoo