ARP Spoofing using Ettercap

Address Resolution Protocol (ARP) spoofing, also known as ARP poisoning, is a type of attack in which an attacker sends falsified ARP messages over a local area network (LAN). This results in the linking of an attacker's MAC address with the IP address of a legitimate computer or server on the network. Once the attacker has linked their MAC address with the IP address of a legitimate device, they can intercept, modify, or even block data transmissions between the victim and the default gateway.

Ettercap is a comprehensive suite for man-in-the-middle attacks (MITM). 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 and includes many features for network and host analysis. In this guide, we will focus on using Ettercap for ARP spoofing to intercept passwords.

Prerequisites

Before diving into the ARP spoofing process using Ettercap, ensure you have the following:

• Ettercap: Installed on your system. It's available in the repositories of most Linux distributions.
• Network Access: Ensure you have permission to access the network and perform ARP spoofing. Unauthorized ARP spoofing is illegal and unethical.
• Target Devices: Identify the devices you want to target for the ARP spoofing attack.

Step 1: Launch Ettercap

Open a terminal and launch Ettercap with the following command:

sudo ettercap -G

This command launches Ettercap in graphical mode. The '-G' flag indicates the graphical interface.

Step 2: Select Sniffing Mode

Once Ettercap is open:

1. Select the network interface you want to use for the attack (e.g., eth0, wlan0).

2. Then click the Check button on the top right to start sniffing.

Step 3: Scan for Hosts

After selecting the sniffing mode:

1. Go to the 'Hosts' menu and select 'Scan for hosts'.

2. Once the scan is complete, go back to the 'Hosts' menu and select 'Host list' to view the detected devices on the network.

Step 4: Set Targets

From the list of detected devices:

1. Select the target device as 'Target 1'.

2. If you want to intercept communications between two devices, select the second device as 'Target 2'. If you only have one target, leave 'Target 2' empty.

Step 5: ARP Poisoning

With the targets set:

1. Go to the 'Mitm' (Man-in-the-Middle) menu and select 'ARP poisoning'.

2. A dialog box will appear. Check the box for 'Sniff remote connections' and click 'OK'.

Step 6: Start Sniffing

Now, to start the ARP spoofing attack:

1. Click the Play "arrow" button at the top left header, if it isn't already on. If it already on it will show a Square button to stop the attack.

Step 7: Intercept Passwords

With the ARP spoofing attack in progress, you can now intercept passwords and other sensitive information. To do this:

1. Go to the 'Plugins' menu and select 'Manage plugins'.

2. Double-click on the 'search_promisc' plugin to activate it. This plugin searches for passwords in the intercepted data.

Conclusion

ARP spoofing using Ettercap is a powerful technique for intercepting data on a network. However, it's crucial to use this knowledge responsibly and ethically. Always ensure you have the necessary permissions before conducting any ARP spoofing attacks. Remember, ethical hacking is about improving security, not exploiting it.