What is a botnet?

A botnet refers to a network of infected computers, often referred to as "zombies," that are under the control of a malicious actor or attacker. This control typically occurs without the consent of the computer owners, as their machines have been compromised by malware. The primary purpose of a botnet is to perform automated tasks, often for illicit purposes, such as sending spam emails, launching Distributed Denial of Service (DDoS) attacks, or stealing sensitive information.

The defining characteristic of a botnet is the command and control aspect; the attacker can remotely operate and manage the infected machines to execute various tasks simultaneously. This makes botnets particularly dangerous and effective for executing large-scale cyber attacks. The coordinated nature of these compromised devices allows for immense processing power and bandwidth to be harnessed, which an individual computer alone could not achieve.

In contrast, the other options describe legitimate uses of computers or networks but do not capture the malicious and controlled nature of a botnet. For example, a collection of networked computers performing shared tasks does not imply that they are being manipulated for harmful purposes. Similarly, a decentralized system for data processing reflects a collaborative model rather than exploitation, and a group of software applications performing analytical tasks does not necessarily involve the control or