What is a Botnet?
A Botnet is a network of hijacked Internet-connected devices that are infected with malware. These infected computers are called zombies, and they’re controlled by a hacker/cybercriminal known as the “Bot herder.” Cybercriminals often rent access to their botnets on the black market or through ad-supported phishing attacks. These bots are used to perform a variety of malicious tasks including Distributed Denial of Service attacks, ad fraud and form grabbing to steal online credentials.
The first step in creating a botnet involves infecting a large number of connected devices with malware that is remotely controlled by the attacker. The malware is spread by web downloads, exploit kits, popup ads and email attachments. Once the devices are infected, they’re then used for tasks that remain hidden to the device owners. The attacker will often use the computing power and functionality of thousands, if not millions of devices to carry out attacks like DDoS attacks, spamming or ad fraud.
Depending on how they’re designed, the bot herder can communicate with infected devices using centralized C&C servers or a P2P approach where each device acts as both a client and a server. Generally, centralized models are easier to control but are also more vulnerable to points of failure.
The increasing use of cheap, Internet-capable IoT devices makes them a popular target for botnet attacks. This has led to a booming industry in ethical hacking and cyber security training. Simplilearn’s Advanced Executive Program in Cyber Security is an ideal program for those looking to build their skill-set in these areas.