What is a huge network of compromised systems and can be used by an attacker to launch denial-of-service attacks?

• A. Bots
• B. Botnet
• C. Local Subnet Scanning
• D. Permutation Scanning

Answer: (B)

A botnet is a large network of compromised systems that an attacker can control to carry out coordinated actions, such as denial-of-service attacks. Each infected device becomes a bot (a zombie) under the attacker’s command, and together they form a distributed army that can simultaneous flood a target with traffic or requests. This distributed nature makes the attack harder to defend against, because the traffic comes from many different machines across the internet, not just one source.

A single compromised device is a bot, but the term botnet specifically refers to the whole network of these bots under centralized control, which is why it’s the best answer for describing a huge network used to launch DoS attacks. Local subnet scanning and permutation scanning are techniques used in discovery and probing of networks, not networks of compromised devices used for attacks.