What is DOS attack and How to Hack using DOS

Guys, you may have seen Mr. Robot and remember the event when Fsociety  use the DDoS as a calling card to lure Elliot into helping them take  down E-Corp or you may have been struck in situation when you try to  open a Website  only to see a notification that Website is down. What is  this? Yes, this is a DOS Attack.

A denial of service (DoS) attack is an attack that clogs up so much  memory on the target system that it can not serve it’s users, or it  causes the target system to crash, reboot, or otherwise deny services to  legitimate users.There are several different kinds of dos attack as discussed below :

1. Ping Of Death :- The ping of death attack sends oversized ICMP datagrams (encapsulated in IP packets) to the victim.The  Ping command makes use of the ICMP echo request and echo reply messages  and it’s commonly used to determine whether the remote host is alive.  In a ping of death attack, however, ping causes the remote system to  hang, reboot or crash. To do so the attacker uses, the ping command in  conjuction with -l argument (used to specify the size of the packet  sent) to ping the target system that exceeds the maximum bytes allowed  by TCP/IP (65,536).
   example:- c:/>ping -l 65540 hostname
   Fortunately, nearly all operating systems these days are not vulnerable to the ping of death attack.
2. Teardrop Attack :- Whenever data is sent over the  internet, it is broken into fragments at the source system and  reassembled at the destination system. For example you need to send  3,000 bytes of data from one system to another
3. SYN – Flood Attack :- In SYN flooding attack, several SYN packets are  sent to the target host, all with an invalid source IP address. When the  target system receives these SYN packets, it tries to respond to each  one with a SYN/ACK packet but as all the source IP addresses are invalid  the target system goes into wait state for ACK message to receive from  source. Eventually, due to large number of connection requests, the  target systems’ memory is consumed. In order to actually affect the target system, a large number of SYN packets with invalid IP addresses must be sent.
4. Land Attack :- A land attack is similar to SYN attack,  the only difference being that instead of including an invalid IP  address, the SYN packet include the IP address of the target sysetm  itself. As a result an infinite loop is created within the target  system, which ultimately hangs and crashes.Windows NT before Service  Pack 4 are vulnerable to this attack.
5. Smurf Attack :- There are 3 players in the smurf  attack–the attacker,the intermediary (which can also be a victim) and  the victim. In most scenarios the attacker spoofs the IP source address  as the IP of the intended victim to the intermediary network broadcast  address. Every host on the intermediary network replies, flooding the  victim and the intermediary network with network traffic.
   Result:- Performance may be degraded such that the victim, the victim  and intermediary networks become congested and unusable, i.e. clogging  the network and preventing legitimate users from obtaining network  services.
6. UDP – Flood Attack :- Two UDP services: echo (which  echos back any character received) and chargen (which generates  character) were used in the past for network testing and are enabled by  default on most systems. These services can be used to launch a DOS  attack by connecting the chargen to echo ports on the same or another  machine and generating large amounts of networktraffic.

The most popular DDoS and dos attack tools are:

• Trin00 (WinTrinoo)
• Tribe Flood Network (TFN) (TFN2k)
• Shaft
• LOIC(LOW ORBIT ION CANNON)
• XOIC 

No softwares, you wanna try it yourself, you can use HPING (comes preinstalled in KALI LINUX).

 OR Download hping from www.hping.org

Steps to hack using DOS attack : CLICK HERE