Dshell

An extensible network forensic analysis framework. Enables rapid development of plugins to support the dissection of network packet captures.

Key features:

Robust stream reassembly
IPv4 and IPv6 support
Custom output handlers
Chainable decoders

Prerequisites

Linux (developed on Ubuntu 12.04)
Python 2.7
pygeoip, GNU Lesser GPL
- MaxMind GeoIP Legacy datasets
PyCrypto, custom license
dpkt, New BSD License
IPy, BSD 2-Clause License
pypcap, New BSD License

Installation

Install all of the necessary Python modules listed above. Many of them are available via pip and/or apt-get. Pygeoip is not yet available as a package and must be installed with pip or manually. All except dpkt are available with pip.
sudo apt-get install python-crypto python-dpkt python-ipy python-pypcap
sudo pip install pygeoip
Configure pygeoip by moving the MaxMind data files (GeoIP.dat, GeoIPv6.dat, GeoIPASNum.dat, GeoIPASNumv6.dat) to /share/GeoIP/
Run make. This will build Dshell.
Run ./dshell. This is Dshell. If you get a Dshell> prompt, you're good to go!

Basic usage

decode -l
- This will list all available decoders alongside basic information about them
decode -h
- Show generic command-line flags available to most decoders
decode -d <decoder>
- Display information about a decoder, including available command-line flags
decode -d <decoder> <pcap>
- Run the selected decoder on a pcap file

Usage Examples

Showing DNS lookups in sample traffic

Dshell> decode -d dns ~/pcap/dns.cap
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 39867 PTR? 66.192.9.104 / PTR: 66-192-9-104.gen.twtelecom.net **
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 30144 A? www.netbsd.org / A: 204.152.190.12 (ttl 82159s) **
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 61652 AAAA? www.netbsd.org / AAAA: 2001:4f8:4:7:2e0:81ff:fe52:9a6b (ttl 86400s) **
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 32569 AAAA? www.netbsd.org / AAAA: 2001:4f8:4:7:2e0:81ff:fe52:9a6b (ttl 86340s) **
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 36275 AAAA? www.google.com / CNAME: www.l.google.com **
dns 2005-03-30 03:47:46    192.168.170.8:32795 ->   192.168.170.20:53    ** 9837 AAAA? www.example.notginh / NXDOMAIN **
dns 2005-03-30 03:52:17    192.168.170.8:32796 <-   192.168.170.20:53    ** 23123 PTR? 127.0.0.1 / PTR: localhost **
dns 2005-03-30 03:52:25   192.168.170.56:1711  <-      217.13.4.24:53    ** 30307 A? GRIMM.utelsystems.local / NXDOMAIN **
dns 2005-03-30 03:52:17   192.168.170.56:1710  <-      217.13.4.24:53    ** 53344 A? GRIMM.utelsystems.local / NXDOMAIN **

Following and reassembling a stream in sample traffic

Dshell> decode -d followstream ~/pcap/v6-http.cap
Connection 1 (TCP)
Start: 2007-08-05 19:16:44.189852 UTC
  End: 2007-08-05 19:16:44.204687 UTC
2001:6f8:102d:0:2d0:9ff:fee3:e8de:59201 -> 2001:6f8:900:7c0::2:80 (240 bytes)
2001:6f8:900:7c0::2:80 -> 2001:6f8:102d:0:2d0:9ff:fee3:e8de:59201 (2259 bytes)

GET / HTTP/1.0
Host: cl-1985.ham-01.de.sixxs.net
Accept: text/html, text/plain, text/css, text/sgml, */*;q=0.01
Accept-Encoding: gzip, bzip2
Accept-Language: en
User-Agent: Lynx/2.8.6rel.2 libwww-FM/2.14 SSL-MM/1.4.1 OpenSSL/0.9.8b

HTTP/1.1 200 OK
Date: Sun, 05 Aug 2007 19:16:44 GMT
Server: Apache
Content-Length: 2121
Connection: close
Content-Type: text/html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<html>
 <head>
  <title>Index of /</title>
 </head>
 <body>
<h1>Index of /</h1>
<pre><img src="/icons/blank.gif" alt="Icon "> <a href="?C=N;O=D">Name</a>                    <a href="?C=M;O=A">Last modified</a>      <a href="?C=S;O=A">Size</a>  <a href="?C=D;O=A">Description</a><hr><img src="/icons/folder.gif" alt="[DIR]"> <a href="202-vorbereitung/">202-vorbereitung/</a>       06-Jul-2007 14:31    -   
<img src="/icons/layout.gif" alt="[   ]"> <a href="Efficient_Video_on_demand_over_Multicast.pdf">Efficient_Video_on_d..&gt;</a> 19-Dec-2006 03:17  291K  
<img src="/icons/unknown.gif" alt="[   ]"> <a href="Welcome%20Stranger!!!">Welcome Stranger!!!</a>     28-Dec-2006 03:46    0   
<img src="/icons/text.gif" alt="[TXT]"> <a href="barschel.htm">barschel.htm</a>            31-Jul-2007 02:21   44K  
<img src="/icons/folder.gif" alt="[DIR]"> <a href="bnd/">bnd/</a>                    30-Dec-2006 08:59    -   
<img src="/icons/folder.gif" alt="[DIR]"> <a href="cia/">cia/</a>                    28-Jun-2007 00:04    -   
<img src="/icons/layout.gif" alt="[   ]"> <a href="cisco_ccna_640-801_command_reference_guide.pdf">cisco_ccna_640-801_c..&gt;</a> 28-Dec-2006 03:48  236K  
<img src="/icons/folder.gif" alt="[DIR]"> <a href="doc/">doc/</a>                    19-Sep-2006 01:43    -   
<img src="/icons/folder.gif" alt="[DIR]"> <a href="freenetproto/">freenetproto/</a>           06-Dec-2006 09:00    -   
<img src="/icons/folder.gif" alt="[DIR]"> <a href="korrupt/">korrupt/</a>                03-Jul-2007 11:57    -   
<img src="/icons/folder.gif" alt="[DIR]"> <a href="mp3_technosets/">mp3_technosets/</a>         04-Jul-2007 08:56    -   
<img src="/icons/text.gif" alt="[TXT]"> <a href="neues_von_rainald_goetz.htm">neues_von_rainald_go..&gt;</a> 21-Mar-2007 23:27   31K  
<img src="/icons/text.gif" alt="[TXT]"> <a href="neues_von_rainald_goetz0.htm">neues_von_rainald_go..&gt;</a> 21-Mar-2007 23:29   36K  
<img src="/icons/layout.gif" alt="[   ]"> <a href="pruef.pdf">pruef.pdf</a>               28-Dec-2006 07:48   88K  
<hr></pre>
</body></html>

Chaining decoders to view flow data for a specific country code in sample traffic (note: TCP handshakes are not included in the packet count)

Dshell> decode -d country+netflow --country_code=JP ~/pcap/SkypeIRC.cap
2006-08-25 19:32:20.651502       192.168.1.2 ->  202.232.205.123  (-- -> JP)  UDP   60583   33436     1      0       36        0  0.0000s
2006-08-25 19:32:20.766761       192.168.1.2 ->  202.232.205.123  (-- -> JP)  UDP   60583   33438     1      0       36        0  0.0000s
2006-08-25 19:32:20.634046       192.168.1.2 ->  202.232.205.123  (-- -> JP)  UDP   60583   33435     1      0       36        0  0.0000s
2006-08-25 19:32:20.747503       192.168.1.2 ->  202.232.205.123  (-- -> JP)  UDP   60583   33437     1      0       36        0  0.0000s

Collecting netflow data for sample traffic with vlan headers, then tracking the connection to a specific IP address

Dshell> decode -d netflow ~/pcap/vlan.cap
1999-11-05 18:20:43.170500    131.151.20.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:42.063074     131.151.32.71 ->   131.151.32.255  (US -> US)  UDP     138     138     1      0      201        0  0.0000s
1999-11-05 18:20:43.096540     131.151.1.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.079765     131.151.5.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:41.521798    131.151.104.96 ->  131.151.107.255  (US -> US)  UDP     137     137     3      0      150        0  1.5020s
1999-11-05 18:20:43.087010     131.151.6.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.368210   131.151.111.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.250410    131.151.32.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.115330    131.151.10.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.375145   131.151.115.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:43.363348   131.151.107.254 ->  255.255.255.255  (US -> --)  UDP     520     520     1      0       24        0  0.0000s
1999-11-05 18:20:40.112031      131.151.5.55 ->    131.151.5.255  (US -> US)  UDP     138     138     1      0      201        0  0.0000s
1999-11-05 18:20:43.183825     131.151.32.79 ->   131.151.32.255  (US -> US)  UDP     138     138     1      0      201        0  0.0000s

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

README.md

README.md

Dshell

Prerequisites

Installation

Basic usage

Usage Examples

Files

README.md

Latest commit

History

README.md

File metadata and controls

Dshell

Prerequisites

Installation

Basic usage

Usage Examples