Botnet click fraud at record high

By Dan Goodin in San Francisco
The Register
23rd October 2009

Malware-infected computers are increasingly being used to perpetrate click fraud, according to a study released Thursday that found their contribution was the highest since researchers began compiling statistics on the crime.

In the third quarter of this year, 42.6 percent of fraudulent clicks were generated by computers that were part of botnets, compared with
36.9 percent the previous quarter and about 27.6 percent in the same period of 2008. The increase comes as criminals trying to profit from click fraud take advantage of new advances in malware that make the practice harder to detect.

"As the botnets get more sophisticated, they're able to perpetrate more click fraud," said Paul Pellman, CEO of Click Forensics, the advertising auditing firm that prepared the report. "They're finding new ways of being distributed, and that's reflected in the data."

The jump in botnet use over the past year comes as the overall amount of click fraud dropped, from 16 percent of all paid ads in Q3 of 2008 to
14.1 percent last quarter. That means manual forms of click fraud, in which large numbers of individuals engage in the practice, has decreased by an even larger margin. Many of those people get paid to knowingly gin the advertising results, while others are tricked into it.