Denial of Service Attack

ghdhair100 · Wysłany: Pon 5:40, 21 Mar 2011

Denial of Service Attack
Imagine a group of junior high school kids who decide to play a prank on their least favorite teacher. They agree that they will all call the teacher抯 phone,[link widoczny dla zalogowanych], as quickly as they can dial,[link widoczny dla zalogowanych], non-stop, until he unplugs the phone in frustration.
When this happens using the Internet rather than telephones, it抯 called a Denial of Service attack. Such attacks are designed to either keep the target system so busy handling the attack that it can抰 get anything else done, or to overwhelm it into shutting down completely.
Why should anyone but a system administrator worry about denial of service attacks? Users need to be aware of something called a BotNet.
The MyDoom virus was one of the first viruses to attempt two levels of attack. First, the virus would try to spread. On infection, though, it would insert a second program into the system. Basically, on MyDoom抯 trigger date (February 1st, 2004), any infected system would launch a denial of service attack against MyDoom抯 real target.
The virus tried to establish a collection of computers that would all launch attacks on the same day. This collection is a botnet,[link widoczny dla zalogowanych], and in the years since MyDoom pioneered the concept, literally dozens of programs have expanded on the idea.
A popular program in use today is Stacheldraht. Stacheldraht is the master program, and it manages a collection of 揾andler� computers. Each of these handlers can control up to a thousand 搝ombie� computers around the world. The hacker with the Stacheldraht master says 揳ttack this server,� the handlers pass the word along, and thousands of systems instantly change from peaceful home computers into remote-controlled computer attackers..
Sure, it sounds like a line from a bad horror movie, but it抯 true. Users need to keep their systems from becoming one of Stacheldraht抯 zombies.
The exclusionThe head teacher wrote to the parents of R and F telling them that neither R nor F could come back to school, but that they would be given help in completing their course at home. He should, of course, have told the parents immediately, ideally by telephone followed by a letter, of their right to make representations to the governing body.

[link widoczny dla zalogowanych]