Scapy

Scapy is a powerful Python-based interactive packet manipulation program and library.

It is able to forge or decode packets of a wide number of protocols, send them on the wire, capture them, store or read them using pcap files, match requests and replies, and much more. It is designed to allow fast packet prototyping by using default values that work.

It can easily handle most classical tasks like scanning, tracerouting, probing, unit tests, attacks or network discovery (it can replace hping, 85% of nmap, arpspoof, arp-sk, arping, tcpdump, wireshark, p0f, etc.). It also performs very well at a lot of other specific tasks that most other tools can't handle, like sending invalid frames, injecting your own 802.11 frames, combining techniques (VLAN hopping+ARP cache poisoning, VoIP decoding on WEP protected channel, ...), etc.

Scapy supports Python 2.7 and Python 3 (3.4 to 3.6). It's intended to be cross platform, and runs on many different platforms (Linux, OSX, *BSD, and Windows).

Hands-on

Interactive shell

Scapy can easily be used as an interactive shell to interact with the network. The following example shows how to send an ICMP Echo Request message to github.com, then display the reply source IP address:

sudo ./run_scapy 
Welcome to Scapy
>>> p = IP(dst="github.com")/ICMP()
>>> r = sr1(p)
Begin emission:
.Finished to send 1 packets.
*
Received 2 packets, got 1 answers, remaining 0 packets
>>> r[IP].src
'192.30.253.113'

Python module

It is straightforward to use Scapy as a regular Python module, for example to check if a TCP port is opened. First, save the following code in a file names send_tcp_syn.py

from scapy.all import *
conf.verb = 0

p = IP(dst="github.com")/TCP()
r = sr1(p)
print(r.summary())

Then, launch the script with:

sudo python send_tcp_syn.py
IP / TCP 192.30.253.113:http > 192.168.46.10:ftp_data SA / Padding

Resources

To begin with Scapy, you should check the notebook hands-on and the interactive tutorial. If you want to learn more, see the quick demo: an interactive session (some examples may be outdated), or play with the HTTP/2 and TLS notebooks.

The documentation contains more advanced use cases, and examples.

Installation

Scapy works without any external Python modules on Linux and BSD like operating systems. On Windows, you need to install some mandatory dependencies as described in the documentation.

On most systems, using Scapy is as simple as running the following commands:

git clone https://github.com/secdev/scapy
cd scapy
./run_scapy

To benefit from all Scapy features, such as plotting, you might want to install Python modules, such as matplotlib or cryptography. See the documentation and follow the instructions to install them.

Contributing

Want to contribute? Great! Please take a few minutes to read this!