A Distributed Denial of Service (DDoS) attack employs very large numbers of attacking computers called "bots" to overwhelm the target with fake traffic. To achieve the necessary scale, DDoS are often performed by botnets which can co-opt millions of infected machines to unwittingly participate in the attack, even though they are not the target of the attack itself. Instead, the attacker leverages the massive number infected machines to flood the remote target with traffic and cause a DoS.