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