Berlin, September 25, 2012 - The Research Team at eleven, leading German e-mail security provider, published five tips today to help users prevent a botnet infection on their computer. Botnets are groups of hijacked private and corporate computers controlled remotely and which are used, among other things, to send spam, usually without the user's knowledge. Undetected, the installed malware often only runs in the background, making it more difficult for users to identify the risk and react accordingly. It is currently estimated that over 90% of all spam e-mails are distributed via botnets. The significant decline in spam on weekends indicates that in addition to private computers, many corporate computers are now affected as well. eleven analyzed the most important infection pathways so that users know what to avoid.