What are two purposes of botnets?

Botnets serve multiple malicious purposes, primarily leveraging a network of compromised devices controlled by an attacker. One key function of botnets is to transmit viruses or spam to computers, effectively spreading malware and unwanted communications to a wider audience. This allows attackers to infect additional devices and expand their control, creating a more extensive network of compromised machines.

In the context of the options presented, the purpose of distributing viruses and spam aligns directly with the destructive activities typically associated with botnets. They are utilized to execute coordinated efforts for tasks like sending large volumes of spam emails, which can lead to further infections, data breaches, and other forms of cybercrime.

The focus on protection or bandwidth enhancement does not relate to the primary functions of botnets. Instead, they are fundamentally used to execute attacks, manipulate networks, and inflict harm on unsuspecting users and their systems.