What is a Botnet?
A botnet is a network of malware-infected devices that are remotely controlled by attackers. The attackers can use the infected devices to do a variety of things, including launching distributed denial-of-service attacks (DDoS), harvesting passwords, or even breaching corporate networks.
Botnets can be based on either a client/server or peer-to-peer model. The client/server approach is the traditional way to create a botnet. With this method, the bot herder uses a server to transmit commands to the device (zombie computer). However, this method has been proven to be vulnerable to disruptions due to single points of failure.
Peer-to-peer botnets work by using devices to find one another and then communicating through file-sharing techniques, such as P2P chat, or over Internet Relay Chat (IRC). The advantage of this type of botnet is that it is much harder to disrupt the communication link between the bot herder and her army of zombie computers because the bots are constantly probing for other devices with a list of known IP addresses.
Hackers can infect a device to become part of a botnet through many different means, including exploit kits hosted on websites that probe each site visitor’s machine for an exploitable flaw; clicking malicious links; social engineering tactics, such as phishing and spoofing; or by directly infecting the victim with malware. In order to protect themselves from being a bot victim, users must implement layered security measures that include the proper use of software and the latest updates.