MITM using Ettercap

Man In The Middle Attack
The man-in-the-middle attack (also known as a bucket-brigade attack and abbreviated MITM) is a form of active eavesdropping in which the attacker makes independent connections with the victims and relays messages between them, making them believe that they are talking directly to each other over a private connection when in fact the entire conversation is controlled by the attacker.
Ettercap
Ettercap is a suite for man in the middle attacks on LAN (local area network). It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols (even ciphered ones) and includes many feature for network and host analysis. In this tutorial i will explain how to sniff (user names,passwords) in LAN using Ettercap

Configuring Ettercap for the Attack
We will be using Ettercap to perform the MiTM attack, but to do so, we will have to set up Ettercap to use IPTables to forward traffic. To do so, open up a terminal session and type the following (everything after the #)

root@bt:~ # echo 1 > /proc/sys/net/ipv4/ip_forward
This enables IP forwarding. Then, type the following:
root@bt:~ # kedit /usr/local/etc/etter.conf
This will open up a new window within which is a text file that holds all the configuration settings for Ettercap. Look for the following lines in the file, and uncomment them by removing the hashes (except for the one next to ―if‖, then save it and close it:
# if you use iptables:
#redir_command_on = "iptables -t nat -A PREROUTING -i %iface -p tcp --dport %port -j REDIRECT --to-port %rport"
#redir_command_off = "iptables -t nat -D PREROUTING -i %iface -p tcp --dport %port -j REDIRECT --to-port %rport"
to this:
# if you use iptables:
redir_command_on = "iptables -t nat -A PREROUTING -i %iface -p tcp --dport %port -j REDIRECT --to-port %rport"
redir_command_off = "iptables -t nat -D PREROUTING -i %iface -p tcp --dport %port -j REDIRECT --to-port %rport"
We are now ready to proceed to the attack stage. There are several kinds man in the middle attacks that we can perform, But in this tutorial we will see attacks based on the ARP protocol
ARP Poisoning

Address Resolution Protocol (ARP) spoofing, also known as ARP flooding, ARP poisoning or ARP Poison Routing (APR), is a technique used to attack an Ethernet wired or wireless network. ARP Spoofing may allow an attacker to sniff data frames on a local area network (LAN),
Man in the Middle Attack using Ettercap
1. First start the ettercap: It is located in Backtrack >Privilege Escalation >Sniffers >Network Sniffers > ettercap-gtk

2. After installation open Ettercap, select sniff mode> unified sniffing and select your network interface as shown
3. Now scan for hosts in your sub net by going to Hosts —> scan for hosts


4. Now open host list from hosts tab and select the IP address of the victim as target 1 and IP address of the router as target 2
5. You can see the targets we have selected by going to the Target menu> Current target
6. Now start ARP poisoning by going to mitm —> ARP Poisoning

7. Finally start the sniffer by going to start —> start sniffing . Now if victim logs into gmail , face book yahoo mail…etc .we will get the user name and password
8. You will see the username name and password in the bottom window
9. You can cross check the ARP cache by typing ―arp –a‖ in the terminal/command prompt to confirm whether the ARP cache has been modified or not.