10.4 Denial-of-Service Attacks
Denial-of-service attacks have become increasingly common on the Internet today. These kinds of attacks seek to make a computer network—in most cases, a particular web site—unavailable and therefore unusable. Also known as distributed denial-of-service (DDoS) attacks, they are frequently launched by means of inundating a target with an overwhelming amount of network traffic. This traffic may take the form of Internet protocol requests at the IP and TCP layers or application-level requests that target specific applications such as an organization's web server, email server, or FTP server. Denial-of-service attacks are frequently perpetrated through the use of bot networks, as discussed in more detail in Chapter 7.
A number of high-profile, wide-scale DDoS attacks have demonstrated the effects that such an effort can have. One of the best-known and largest attacks was launched against the country of Estonia in May 2007 . It presented a prime example of a politically motivated attack, as it was launched by Russian patriots in retaliation for the removal of a Soviet monument by the Estonian government. Attackers disabled numerous key government systems during a series of attacks that occurred over the course of several weeks.
In 2006, Joe Lieberman's web site also fell victim to a concentrated denial-of-service attack . Forcing the site offline, the attack paralyzed the joe2006.com domain, preventing campaign officials from using their official campaign email accounts and forcing them to revert to their personal accounts for communication.
The implications of such attacks are clear: They prevent voters from reaching campaign web sites, and they prevent campaign officials from communicating with voters.