Which of the following typically uses compromised systems that become part of a bot network?

A DDoS (Distributed Denial of Service) attack is often launched from botnets — networks of compromised systems (bots or zombies) under the control of an attacker. These devices flood the target with traffic to disrupt services.

A. Evil twin attack is a wireless spoofing method.

C. XML injection targets web applications.

D. Brute-force attacks repeatedly guess passwords but don't involve a botnet by default.

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CompTIA Network+ N10-009 Official Objectives: 4.2 – Identify common security threats and vulnerabilities.