If you are unaware of botnet then look at the Wiki information of botnet.
Though linux and Mac systems are said to be less prominent to bot attacks, but if you are on windows system then you need to be worry about it.
You need to cross check your start up items by going to “msconfig†or keep a check of all running process by pressing Alt+ Ctrl + del.
Using a good antivirus along with trojan remover, anti spyware and firewall like comodo is advisable.
Botnet is one of the oldest way to take down any computer and server and people will never get to know about it till the time their credit card or personal data are tempered.
If you are p@r@noid about your security I will suggest you to always keep you system and antivirus update.
