What is a botnet?

A botnet is defined as a collection of internet-connected devices that have been infected and are controlled remotely by malware. This typically includes a multitude of devices such as computers, smartphones, and IoT devices, which can be directed collectively to perform various tasks such as sending spam emails, launching distributed denial-of-service (DDoS) attacks, or mining cryptocurrencies without the owners' consent.

The malware enables the attacker to maintain control over the infected devices, often without the knowledge of the device owners. By leveraging the resources of many compromised devices, botnets are able to perform large-scale attacks and automate malicious activities more efficiently than would be possible with a single system or device.

Recognizing what a botnet is helps to understand the broader context of cybersecurity threats and the importance of protecting devices from malware infections. In contrast, other options do not accurately represent botnets, as they describe different concepts unrelated to the collective control of compromised devices.