Four Ways to Extract Files From Pcaps

It’s time to extract files from pcaps. If you ever played with packet captures you probably thought it would be cool that you could actually get downloaded files so let’s see not only one way to do this, but four!

1. Wireshark: http export

You can find this at File > Export > Objects > Http, you will be presented with a list of files found in all the http requests. The bad thing about this feature is that even with the latest version (1.6.5 at the time of this writing) you still can’t sort by column or apply any filters which makes finding something specific hard.

2. Wireshark: export bytes

To find this you will have to drill down in the packet you want, depending on the protocol.

Right click > Export selected bytes

The advantage of doing it this way is that you can actually extract files from other protocols other than http (like ftp or smb) and you can use display filters.

3. Network miner http://sourceforge.net/projects/networkminer/

Network miner is a tool for network analysis but with a focus on forensic analysis. It can load a pcap and extract files and other data, there is both a free and a commercial version available.

4. Chaosreader

This tool will analyze and extract session information and files and create an html report you can open in any browser

chaosreader http-data.pcap

It will create a lot of files so you may want to launch it inside an empty dir or make a new one and use the -D option, then you can open index.html

Conclusion

If the data crossed the network it has to be there somewhere. In this post we have seen a few tools you can use to uncover these files and extract them for your own benefit.