What is a Botnet?
A botnet is a group of computers, IoT devices and smartphones that are infected with malware and are networked together to carry out cyberattacks on a much larger scale than an individual hacker could do alone. The bots are controlled by a hacker (bot-herder) who can use them for malicious purposes including click fraud, DDoS attacks, form grabbing to steal online credentials, and more.
Once infected with bot malware, hackers recruit devices to join the botnet by exploiting vulnerabilities in software or devices, leveraging social engineering techniques, or using automated scanning tools. Once the botnet reaches a critical size, it will begin to execute malicious tasks as commanded by the hacker.
Bots communicate with the bot-herder through a command and control (C&C) infrastructure to receive new instructions. The C&C server and the bots may operate in a hierarchical model with centralized servers at the top of the hierarchy, or the bots may connect to each other directly via peer-to-peer (P2P) communication. P2P botnets are more resilient and difficult to disrupt than centralized models.
You can protect against the risk of your devices being recruited into a botnet by implementing security measures such as strong passwords and multi-factor authentication (MFA) on all your devices. You should also regularly wipe and update systems to eliminate the presence of malware and prevent unauthorized access by botnets. You can also implement network filtering to block the communication channels used by botnets to reconnect with C&C servers or other compromised devices.