A means of burdening or effectively shutting down a remote system by bombarding it with traffic from many other computers. DDoS attacks are often launched using the compromised systems of Internet users, often using botnets. An attacker will exploit a vulnerability in one computer system and make it the DDoS “master” using Remote Control Software. Later, the intruder will use the master system to identify and manage zombies that can perform the attack.

These are more virulent forms of Denial-of service attacks. Attackers break into and install attack programs on great numbers of insecure computers called zombies (see Zombies). These are all programmed to attack a victim computer at the same time. Because the attacks come from so many sources, such attacks are almost impossible to defend against.. _____________________________________________________________________________

A denial-of-service attack in which the attackers load their malignant code onto a host of other machines (often through Trojan horses). Distributed attacks can cause much more damage than an attack originating from a single machine, as the defending company needs to block dozens or even hundreds of IP addresses.