Shields Up!: Botnets

Today let’s take a look at botnets. This is the tool of choice for spammers everywhere. A botnet is a collection of computers, known as zombies, that have been infected by malware. The malware enables the criminal in charge of the group, also known as the bot master, to control all the infected computers remotely. Botnets are used to send spam, conduct DDoS attacks and distribute even more malware. They range in size from tens of thousands to millions of zombies.

A botnet begins its life as a single or group of servers sending out malware. As more and more computers become infected with the malicious software, the botnet grows. Large botnets are capable of sending out billions of spam messages a day. Most advertise fake pharmaceuticals or porn sites. The infected computers are programmed to contact the control server at specific times to receive updates or new instructions.