ALSO CALLED: Distributed Denial of Service Attacks, Teardrop Attacks, Denial of Service Prevention, DOSA, Packet Monkey, Attacks, DDoS Attacks, DNS Attacks, Smurfing, Denial-of-service Attack, D o S Attacks, DoS Attacks, and Smurf
DEFINITION: On the Internet, a distributed denial-of-service (DDoS) attack is one in which a multitude of compromised systems attack a single target, thereby causing denial of service for users of the targeted system. The flood of incoming messages to the target system essentially forces it to shut down, thereby denying service to the system to legitimate users.

A hacker (or, if you  … 
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DENIAL OF SERVICE ATTACKS DEFINITION (continued): …  prefer, cracker) begins a DDoS attack by exploiting a vulnerability in one computer system and making it the DDoS "master." It is from the master system that the intruder identifies and communicates with other systems that can be compromised. The intruder loads cracking tools available on the Internet on multiple -- sometimes thousands of -- compromised systems. With a single command, the intruder instructs the controlled machines to launch one of many flood attacks against a specified target. The inundation of packets to the target causes a denial of service.

While … 
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