Often in the course of investigating a compromised machine or when analyzing malware in a sandnet or honeynet, I will have a complete capture of all the network activity in a pcap file and I want to pull out any files that were downloaded by the infected machine.  Unfortunately, I have not found any really good tools that allow me to full files from lots of different types of traffic.  A couple of years ago, I put together a perl script that used tcptrace and the HTTP::Response perl module to pull downloaded files out of HTTP traffic, but what about other forms of traffic?  FTP?  SMTP?  unknown TCP or UDP?  whatever?  My ideal tool would be able to reassemble the packets, discard headers, etc.  Well, the other day I noticed a post on Darknet about Xplico that might be (at least the basis of) the magic tool I'm looking for.  I'm just starting to play with it, but I figured this might be a good time to ask our readers what they use?  You can send us e-mail, use the contact form, or leave a comment.  Thanx in advance.

Update: 2009-08-16 00:15 GMT (jac)  A huge thanx to all who wrote in, here are some of the tools you suggested.

• NetworkMiner ( thanx, Russ and Dentrasi.  Just found this note on running it under wine on Linux)
• tcpxtract (suggested by John R, Chris and Doug)
• Bro (suggested by Nicholas)
• tcpflow (suggested by Ratufa and Chris)
• foremost (suggested by Chris and Doug)
• the dsniff suite (suggested by Chris and Jason)
• Chaosreader (suggested by Chris and Parveen)
• pyflag (suggested by Chris)
• tcptrace (suggested by John T)
• tcpick (suggested by Doug)
• xtract.py from npeid (suggested by anonymous)

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Jim Clausing, jclausing --at-- isc dot sans dot org