One of the researchers at Qualsys Labs has created a proof-of-concept denial-of-service (DOS) attack that, in theory, could turn a speedy server into a slow computer virtually undetected. How? Simply by changing the way a server must respond to an incoming packet of information.

Slow DOS Attack Concept Not New

The idea of attacking a Web server one piece at a time isn’t new. In 2009, Slowloris demonstrated the “death-by-a-thousand-HTTP-requests” approach, in which partial page requests are dribbled out in a maddeningly slow fashion. After awhile, Slowloris can clog up most or all available TCP ports, effectively stopping the server in its tracks.

The latest evolution of the slow death takes a different approach. Instead of issuing partial requests, Slow Read issues full page requests but then slows down the server by reading the response ever so slowly. In addition, the attack could exploit the variable TCP packet size to create zillions of exceedingly tiny packets, which are then read oh-so-slowly. The server, which is ready to send data, must hold unread packets in a buffer, waiting for the attacker to request more data. If a number of malefactors applied this to the same server, the server would simply stop working for legitimate users as it waited to ship little, tiny data packets to the slow readers of the world.

The result: one seriously slow computer. What is the likelihood that the Internet will suddenly screech to a halt with this? Not much. Server admins can prevent this kind of attack by configuring Web servers (or any server – really – that uses TCP/IP) to refuse connections to requestors that set unreasonably small data packet sizes. They could also address the issue by timing out requests. If a page request can’t be completed (on the recipient’s side) within a certain reasonable period of time, the connection could be (and should be) dropped.

The theoretical attack, however, does underscore the role of data transmission in computer performance. Sometimes computers that are connected to a network are exceedingly slow – not because something’s wrong with them – but because something’s wrong with the computer on the other end of the connection.

That’s always something to take into consideration when trying to troubleshoot a computer problem. If the problem occurs during a network connection, disconnect the computer from the network. If performance improves, you know that the problem is related to the network connection and not to the computer in question.

Photo Credit: ivanpw, via Flickr

If you think you have a slow computer, you probably do. Over time, a computer accumulates a lot of junk that decreases its performance noticeably. It may be tempting to scuttle your hard disk and start all over, or worse, buy a new computer. In many cases, your technology isn’t the problem, but your registry might be.

A Windows registry filled with useless entries, abandoned registry keys, and other worthless entries can slow down your computer, cause conflicts among programs, make your computer freeze or crash, and diminish the performance of an otherwise perfectly good computer. You may notice performance changes right away, or your computer’s performance may slip away little by little, until you can’t get your computer to do anything at all. You may start to see Windows errors, or the frequency of errors may increase. All of these are signs that your computer is in trouble.

Why Is The Registry So Troublesome?

Why is the registry so much trouble? As you use the computer, new entries are written into the registry. In a perfect world, these entries would be removed when the program they serve is removed, but that doesn’t always happen. Your registry can become loaded with old .com files and ActiveX entries that won’t do anything but cause your system to crash and fail.

These entries aren’t the only things that will cause trouble. Corrupted font files can cause major problems. To get rid of the problems, you need to get rid of these troublesome files.

RegCure To The Rescue!

You don’t have to be a wizard to fix any of these problems. You just need to know where to start. RegCure from ParetoLogic is the choice of millions of PC users for all sorts of registry problems. RegCure cleans your registry and prevents old, abandoned or corrupted registry keys from slowing the performance of your computer. It removes old DLL files that would otherwise sap the speed from your computer.

With RegCure, you’ll be amazed at how much livelier your computer is. Once you’ve got RegCure installed, using the computer will be a pleasant experience again. No freezing, no crashing, no unexpected, annoying or mysterious Windows errors.

Best of all, RegCure is designed to be used by ordinary people. You don’t have to be a computer guru to use RegCure. It installs easily and you can configure it in just minutes. You can also use RegCure to make a full backup of your registry. In case something goes wrong, you can put your system back to the way it was in just moments.

Don’t put up with irritating computer problems. Get rid of them once and for all with RegCure.

Photo Credit: Craig Jewell