PandaLabs has detected a network of computers infected with the bot Clickbot.A, which is being used to defraud ‘pay per click’ systems, registering clicks automatically and providing lucrative returns for the creators. According to the data collected so far, the scam is exploiting a global network comprising more than 34,000 zombie computers (those infected by the bot).
http://www.net-security.org/secworld.php?id=4002