What is a Denial-of-service Attack?
Also known as a distributed denial-of-service attack (DDOS), a denial-of-service attack is an attempt to impede a computer’s intended users from accessing resources latent in the system.
A DDOS is a form of computer virus that severely disrupts the processing speed of the computer’s network.
In most instances, a denial-of-service attack is issued by an individual or organization to prevent an Internet site or service from functioning. As a result of this somewhat broad function, a denial-of-service attack, the means to carry out, the motives to initiate, and the targets of a DDOS will greatly vary based on a case-by-case circumstance.
Perpetrators of a denial-of-service attack will typically target sites or computer services which are hosted on high-profile web networks, such as credit card payment portals, banking sites and root name servers.
A DDOS is considered to be a grave violation of the IAB’s Internet proper use policy. In addition, denial-of-service attacks violate the acceptable use policies aligned with the majority of Internet service providers.
A DDOS is also regarded as illegal in the majority of nations. The legality issues revolving around denial-of-service attacks will fluctuate based on the individual laws of a particular nation.
Methods of Attack
The most common method of a DDOS involves saturating the targeted network with external communication requests so that it cannot respond effectively to legitimate traffic or users. In general terms, denial-of-service attacks are implemented by forcing a targeted computer to shut down or by consuming the target’s resources so that it is unable to provide it basic service. In essence, denial-of-service attacks obstruct the communication media between the intended user and the targeted user so that they can no longer access the Internet or effectively communicate.
A DDOS is performed in five basic ways:
1) Denial-of-service attacks can be delivered through the consumption of the targeted computer’s resources, such as the system’s disk space, its processor, or bandwith.
2) A DDOS can be implemented by disrupting the configuration information (such as the routing information).
3) Denial-of-service attacks can disrupt the physical network components of the targeted computer.
4) A DDOS can be delivered by obstructing the communication media between the intended users and the targeted victim so that they can longer communicate.
5) Denial-of-service attacks can be implemented through the disruption of state information, such as resetting TCP sessions.
In addition to these basic methods, denial-of-service attacks may be incorporated with malware to max out the targeted processor’s usage or to trigger errors in the microcode of the terminal.
Symptoms of a DDOS attack
When a computer or network falls victim to a DDOS attack it will typically possess the following symptoms:
Uncharacteristically slow network performance. Opening files or accessing web sites is extremely delayed;
Inability to access websites or particular websites;
Dramatic increase in the number of solicitation or spam emails received. This form of DDOS is typically classified or known as an e-mail bomb DDOS.