Denial of Service

It’s good to be popular but it definitely comes with it’s own problems.  For instance, today, some clever folks decided to run a Distributed Denial of Service attack on the eBoundHost.com domain name.  They knocked us out of the web for a little bit of time, but luckily our monitoring system sounded an alarm and a tech was dispatched to fix the problem.

What happened?  A standard server simply cannot cope with several hundred servers trying to access a website at the same moment.  At first things work fine, then they slow down and finally, the server runs out of allowed processes.  The Apache web server is now effectively useless, hence the title: Denial of Service attack.

How does the attack happen?  Someone’s grandmother receives an email on her AOL account that promises to have pictures of her favorite relatives.  She opens the picture only to infect her computer with the most nasty Trojan virus known to mankind.  This Trojan proceeds to let his friends know that there is a party happening at grandmas house.  They come to visit and also infect the computer.  All sorts of fun things can be installed this way, for instance, software that turns this computer into a node on a botnet.  This botnet zombie is now fully in control of some 16 year old in Vietnam/Russia/Turkey/etc, and this computer can now participate in things like sending spam or a Denial of Service attack.

There are definitely ways to deal with this kind of situation.  First off, there are devices you can buy that deal with known DDoS patterns.  There are lists of known zombie ip addresses that you can block out on the router.  There are ways to deal with this type of situation.  Luckily this does not have all that often, and it is usually enough to merely let the attack work itself out.

This time the attackers were nice enough to have left us a signature of their work, and for that we are very grateful.  It really made the cleanup effort much easier.  So I wanted to say the following, we know you are out there and we know what you can do, and we are very impressed 😉

Happy holiday weekend everyone!

Artur July 5, 2008