How a denial-of-service attack works

Aug 06, 2009

(AP) -- Some details about denial-of-service attacks, like the one Thursday against Twitter.

To picture a "denial-of-service" attack, think about what would happen if you and all your friends called the same restaurant over and over and ordered things you didn't even really want. You'd jam the phone lines and overwhelm the kitchen to the point that it couldn't take any more new orders.

That's what happens to Web sites when criminals and hackers hit them with denial-of-service attacks. They're knocked offline by too many junk requests from computers controlled by the attackers.

The bad guys' main weapons in such an attack are "botnets," or networks of "zombie" personal computers they've infected with a . The virus lets the criminals remotely control innocent people's machines, which are programmed to contact certain Web sites over and over until that overwhelms the servers that host the sites. The servers become too busy to respond to anything, and the slows or stops working altogether.

People try denial-of-service attacks all the time, but assaults are often unsuccessful because Web sites have ways of identifying and intercepting malicious traffic.

Sites that go down generally are less prepared, because they are less accustomed to being hit or aren't sensitive enough to warrant extra precautions.

Popular Web sites, like e-commerce and banking sites, have a lot of experience dealing with denial-of-service attacks, and they have sophisticated software designed to identify malicious traffic.

If your computer is being used in a , you're likely to see a significant slowdown, because your is being siphoned for the assault. But there aren't always obvious signs that your computer has been infected.

So the best thing is to focus on prevention, namely by having up-to-date antivirus software. If you're concerned your machine might be infected, it's wise to run an antivirus scan. Many antivirus companies offer a free scan from their Web sites.

©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Explore further: Dutch student sells his data for €350, but at what price privacy?

add to favorites email to friend print save as pdf

Related Stories

Tech 101: How a denial-of-service attack works

Jul 08, 2009

(AP) -- Investigators are piecing together details about one of the most aggressive computer attacks in recent memory - a powerful "denial-of-service" assault that overwhelmed computers at U.S. and South Korean ...

Report: DDoS attacks big Net threat

Oct 12, 2005

A new report warns that Internet service providers are facing an unrelenting barrage of distributed denial of service attacks aimed at crashing the network.

DOS Extortion Fading

May 01, 2007

The economics of Denial Of Service blackmailing isn't working out, and botnet owners are shifting to other, less risky crimes.

Recommended for you

Researchers uncover likely creator of Bitcoin

4 hours ago

The primary author of the celebrated Bitcoin paper, and therefore probable creator of Bitcoin, is most likely Nick Szabo, a blogger and former George Washington University law professor, according to students ...

White House updating online privacy policy

8 hours ago

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...

Net neutrality balancing act

Apr 17, 2014

Researchers in Italy, writing in the International Journal of Technology, Policy and Management have demonstrated that net neutrality benefits content creator and consumers without compromising provider innovation nor pr ...

User comments : 0

More news stories

Under some LED bulbs whites aren't 'whiter than white'

For years, companies have been adding whiteners to laundry detergent, paints, plastics, paper and fabrics to make whites look "whiter than white," but now, with a switch away from incandescent and fluorescent lighting, different ...

Researchers uncover likely creator of Bitcoin

The primary author of the celebrated Bitcoin paper, and therefore probable creator of Bitcoin, is most likely Nick Szabo, a blogger and former George Washington University law professor, according to students ...

The importance of plumes

The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided ...