Distributed denial-of-service (DDoS) Attack

"This post explains DDoS attacks in detail, and also highlights the comparison & advantages over DoS Attacks"

A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users.

• DDoS attacks require engagement of multiple machines, which will be sending the attack traffic to the victim.
• The attacking machines donot belong to the attacker and are frequently called zombies, daemons, slaves, or agents.
• Agents(Zombies) are usually poorly secured systems at universities, companies, and homes—even at government institutions.
  
• The attacker breaks into them, takes full control, installs DDoS software on them and launch coordinated attacks them for the attack.
• Automated tools discover potential agent machines, break into them, and install the attack code upon a single command from an attacker, and report success back to her.
• The master program, at a designated time, then communicates to any number of "agent" programs, installed on computers anywhere on the Internet. The agents, when they receive the command, initiate the attack.
• This makes it difficult to detect because attacks originate from several IP addresses.
• If a single IP address is attacking a company, it can block that address at its firewall. If it is 30000 this is extremely difficult.

TOOLS : Shaft, Trinoo, Tribe Flood Network (TFN), Stacheldraht, Tribe Flood Network 200 (TFN2K)