-: Denial Of Service (DoS) Attacks :-
7) Distributed Denial Of Service (DDoS) :- In
Distributed DoS attack, there are 100 or more different attackers
(systems) attacking the single system. Due to higher number of attackers
DDoS attack is more effective and dangerous than regular DoS attack.
The attackers have control over master zombies, which, in turn, have
control over slave zombies, as shown in figure.
No system connected to the internet is safe from DDoS
attacks. All platforms, including Unix and Windows NT, are vulnerable to
such attacks. Even Mac OS machines have been used to conduct DDoS attacks.
The most popular DDoS tools are:-
a) Trin00 (WinTrinoo)
b) Tribe Flood Network (TFN) (TFN2k)
8) Distributed Denial
Of Service with Reflectors (DRDoS) :- In
DRDoS attacks the army of the attacker consists of master zombies,
slave zombies, and reflectors. The difference in this type of attack
is that slave zombies are led by master zombies to send a stream of
packets with the victim's IP address as the source IP address to other
uninfected machines (known as reflectors), exhorting these machines
to connect with the victim. Then the reflectors send the victim a
greater volume of traffic, as a reply to its exhortation for the opening
of a new connection, because they believe that the victim was the
host that asked for it. Therefore, in DRDoS attacks, the attack is
mounted by noncompromised machines, which mount the attack without
being aware of the action.
a DRDoS attack creates a greater volume of traffic because of its
more distributed nature, as shown in the figure below.