<Li> long - term denial of access to the web or any internet services . </Li> <P> If the attack is conducted on a sufficiently large scale, entire geographical regions of Internet connectivity can be compromised without the attacker's knowledge or intent by incorrectly configured or flimsy network infrastructure equipment . </P> <P> A wide array of programs are used to launch DoS - attacks . </P> <P> In cases such as MyDoom the tools are embedded in malware, and launch their attacks without the knowledge of the system owner . Stacheldraht is a classic example of a DDoS tool . It utilizes a layered structure where the attacker uses a client program to connect to handlers, which are compromised systems that issue commands to the zombie agents, which in turn facilitate the DDoS attack . Agents are compromised via the handlers by the attacker, using automated routines to exploit vulnerabilities in programs that accept remote connections running on the targeted remote hosts . Each handler can control up to a thousand agents . </P>

To launch a distributed denial of service (ddos) attack an attacker often uses