The DDos-attack is a reduction from expression in English of Distributed Denial of Service which is translated as "the distributed failure in service". This term means failure from service of a resource as a result of continuous requests. In other words is an attack on a system which pursues the aim to put it out of action.
As a result of the DDos-attack any Internet resource can be completely put out of action – from the small website business card to the largest Internet portal. During a DDos-attack on the website, many thousands requests from users arrive. It leads to a server overload, and subsequently, to its unavailability. The server does not manage to respond to a huge number of requests that it leads to its failure. Well worked DDos-attacks have chaotic character that even more complicates work of a resource.
Feature of the DDos-attacks is their access from the different nodes located in different corners of the world. It does the majority of methods of fight against them inefficient as overlapping of some one node is not enough. Most often the attacks carry out by means of the Trojan programs, involving through them users who do not even suspect about the participation in this process. The Trojan programs get into the unprotected computers of users and long time do not prove in any way. Thus the area of coverage of the DDos-attacks can be almost boundless, and requests can be sent from any corners of the world.
The computer of the user can be infected via the browser at visit of the websites containing the Trojan programs at installation of the counterfeit software or when receiving mail from the unchecked addresses. Operations of the infected computers often are indistinguishable from actions of users that complicates fight against them.
For the first time the DDos-attacks were applied in 1996. However they began to pose a serious threat three years when hackers managed to put out of action the websites of such companies as Amazon, CNN, Yahoo and others later. Now it is rather simple to order such attack, and it costs rather not much. The first in a zone of risk are business companies. Thus it is rather simple to cause a loss to their activity and if the attack is made during the big-budget Internet company on advance – consequences can be catastrophic for the owner of business.
Structure of the DDos-attacks
Now the so-called three-level DDos-attacks are the most popular. During such attacks, the top level occupies several managing computers from which control signals are given. At the second level there are management consoles distributing signals thousands or millions of computers of users which are the third level of a system. Computers of users carry out sending requests for Internet resources which are an ultimate goal of the attack. Due to such structure, feedback cannot be traced, at most it is possible to calculate one of distributive consoles of the second level.
Methods of fight against the DDos-attacks
For fight against the DDos-attacks it is necessary to carry out a number of the preventive measures directed to optimal adjustment of program and network providing, installed on the server and also to state all necessary information to hosting provider. Only in that case, there is a probability of fast and effective fight against the DDos-attack.