What is a botnet?

A botnet refers to a network of infected computers or devices that are controlled by an attacker, typically without the knowledge of the device owners. These compromised machines, known as "bots" or "zombies," can be directed to carry out automated tasks. This often includes activities that have malicious intentions, such as launching distributed denial-of-service (DDoS) attacks, sending spam emails, stealing sensitive information, or facilitating other types of cybercrime. The key characteristic of a botnet is the centralized control by an attacker, enabling coordinated and scalable attacks using a large number of compromised devices.

The other options describe different technologies or concepts: a secure network for managing IoT would involve safe communication protocols, a type of firewall is meant to prevent unauthorized access to a network, and a system for monitoring network traffic focuses on analyzing data flow rather than executing automated tasks. These alternatives do not exhibit the defining features of a botnet, which revolves around the exploitation of multiple devices for harmful activities directed by a malicious actor.