The term botnet is a portmanteau that combines the words ‘robots’ and ‘network.’ Botnets are a form of illicit distributed computing and are composed of 1000s of hijacked machines that are united and commanded from a single point. They are the foot soldiers of large scale organized cyber crime – including massive spam campaigns, cyber theft and DDoS attacks. They’re also used for mercenary purposes – rented out to would be hackers who then use them for their own criminal purposes.

Bots take over your computer through Trojans – which (as we’ve now determined) gain access through your computer by a wide variety of techniques including phishing, spear phishing, piggybacking and baiting.

The mother of all botnets would have to be the Kraken botnet of 2008. At the time it was the world’s largest botnet – infecting 50 of the Fortune 500 companies. At its peak it was sending 9 billion spam emails a day from a network of 495,000 infected computers. It included sophisticated techniques that avoided detection from the world’s top antivirus programs.

You can protect yourself against botnets by following our 5 best practices and by using a anti-virus programs. If you find your computer appears to be running slowly and lagging, you may be infected.