This chapter deals with attacking the problem of botnets. It reviews the various ways that respond to the challenge of botnets, including the basic security practices for hosts and networks. If a botnet client host is vulnerable to exploitation and not fixed, it is still vulnerable and can probably be infected with a new bug—controlled by a different master, and added to a new, stealthier botnet for new forms of misuse. The primary motivation for the creation and use of botnets is money. Education about keeping computers safe has always been a problem in security. Several effective practices for individual computer users to consider are: if it's spam, delete it and don't respond to it, do not execute unknown e-mail attachments, make sure the system has auto-updates on, and ensure that the local accounts—particularly those with administrator privileges have strong passwords. If one is in an enterprise or organization, one should consider a software that will centrally collect and protect the local event logs from the workstations.