A botnet is a network of infected computers with malwares. Most of the internet users do not even realize that their computers are attacked by botnet. Botnet can do different types of attacks using your IP address and at the same time your PC becomes a remote control robot for illegal activities. Botnet generally connect through bots, an infected network which takes the control of the entire system remotely. This robot can give information to other spams also. A botnet attacker gets control of your computer in many ways through virus or worms. Botnets are powerful because the hackers control thousands and sometimes lakhs of computers remotely to perform some illegal activities online. Hackers use botnets to make a machine unavailable to its users temporarily while others use them as a spam.