DDoS: Distributed Denial of Service Attack

DDoS attack is considered as one of the biggest attacks on the Internet in today's cyberspace. DDoS stands for "Distributed Denial of Service". The DDoS attack is launched using a botnet, I discussed about botnets in the previous post. With the regular increase in the Internet traffic it's pretty easy for the attackers to acquire huge number of systems and convert them into bots and then use them to launch a botnet attack on any desired target. The most popular target of DDoS attacks are websites.

The basic agenda behind launching a DDoS attack is to take down  a web site so that users can't access the services provided by that website. Now if a website provides all it's services online or is a e-commerce website like Amazon the website downtime is equal to closed store which can result in huge revenue losses and lost in customer confidence.

How is a DDoS attack launched?

Following steps are involved in a DDoS attack:

1. The attacker sends a command to all the bot clients to redirect their internet traffic to a specific web address which the attacker is trying to target (say www.xyz.com).
2. The bot clients receive the command, execute it and redirect their internet traffic to the target website. 
3. When the internet traffic rate crosses the bandwidth limit of the target website the website goes down and remains down until attacker finishes the attack.