Section: Threats and Vulnerabilities
Explanation/Reference:
Explanation:
A Distributed Denial of Service (DDoS) attack is an attack from several different computers targeting a
single computer.
One common method of attack involves saturating the target machine with external communications
requests, so much so that it cannot respond to legitimate traffic, or responds so slowly as to be rendered
essentially unavailable. Such attacks usually lead to a server overload.
A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or
resources of a targeted system, usually one or more web servers. Such an attack is often the result of
multiple compromised systems (for example a botnet) flooding the targeted system with traffic. When a
server is overloaded with connections, new connections can no longer be accepted. The major advantages
to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more
attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine,
and that the behavior of each attack machine can be stealthier, making it harder to track and shut down.
These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing
more incoming bandwidth than the current volume of the attack might not help, because the attacker might
be able to simply add more attack machines. This after all will end up completely crashing a website for
periods of time.
Malware can carry DDoS attack mechanisms; one of the better-known examples of this was MyDoom. Its
DoS mechanism was triggered on a specific date and time. This type of DDoS involved hardcoding the
target IP address prior to release of the malware and no further interaction was necessary to launch the
attack.