Posts Tagged ‘internet security’
What Is a Denial of Service (DoS) Attack?
The name of this attack, “denial of service” (DoS), refers to the intended result. Also known as a “distributed denial-of-service attack (DDoS attack), these types of attacks attempt to make a Web site unresponsive, in other words to crash it. Of course the target can be any Internet site or service but the most likely targets are high-profile servers.
The perpetrators of these attacks usually flood the target with massive requests. The servers get overwhelmed and stop responding to legitimate requests. A “successful” denial of service attack forces the target computer to either reset or it consumes so much of the server’s resources that it can no longer provide service to its customers. These attacks are malicious, malevolent, and unethical. Perpetrators may be prosecuted under the laws of some countries.
For more technical information go to http://en.wikipedia.org/wiki/Denial-of-service_attack.
What You Should Know About Conflicker and How You Can Prepare
Conflicker, also known as the Downadup worm, is going to change the way it operates on April 1, 2009 but it is unlikely to cause anything visible. The media has hyped this story but it is still very important we take the threat seriously. Here are a couple of media articles on Conflicker:
http://www.cnn.com/2009/TECH/ptech/01/16/virus.downadup/index.html
http://www.bostonherald.com/business/technology/general/view.bg?articleid=1162343
So what exactly is going to happen April 1st? Conficker has been polling 250 different domain names every day to download and run an update program. On April 1st the latest version of Conficker will start to poll 500 out of 50,000 domains a day to do the same thing. I use the term ‘latest version’ because most of the infected machines are infected with the B variant which became widespread in early January. With B variant nothing happens on April 1st. If you are running a Mac you have nothing to worry about. Also if you have all your Microsoft updates and up-to-date virus protection you are safe. As a precaution you should run a full virus scan on your PC.
I consider this a real threat because of the nature of this worm. First of all it is very sophisticated. It is one of the first world-class worms that use the MD6 cryptographic hash algorithm developed at MIT. For more information on MD6 go to:
http://groups.csail.mit.edu/cis/md6/
The creators are professionals and, as of now, we have no idea who they are up to. As of February 13, 2009, Microsoft has offered a $250,000 reward for information leading to the arrest and conviction of the individuals behind the creation and/or distribution of Conficker. The downloadable virus exploits the autorun feature on Windows machines and installs with admin privileges. Attackers could use this download channel to run any program on all infected machines. The worm also has some peer-to-peer functionality which means that infected computers can communicate with each other without the need for a server. The gang behind this is serious and we should not underestimate them. They could steal your data, send spam, do DDoS, and so on. The fact that we don’t know what they are really after just makes it all a bigger mystery. For a more detailed look at Conflicker go to:
http://en.wikipedia.org/wiki/Conficker
How do you know if you are infected?
- 1. You can’t access antivirus sites like avg.com, kaspersky.com, or security sites like f-secure.com. You also will not be able to access the Microsoft/Windows updates sites.
- 2. You can’t update your antivirus or get Microsoft automatic updates.
What should you do if you are infected? You need to run a cleaning tool. Here is a good one. Please follow the instructions carefully:
http://support.f-secure.com/enu/home/onlineservices/fsec/fsec.shtml
Please remember, to remain uninfected, keep your anti-virus up-to-date and install all the latest Microsoft updates.