Is there a way to check every packet leaving the system for sensitive data like IP addresses, personal information (like logins) etc ?

A free (and preferably open source) program which does this for Linux would be great.

Otherwise, where would I start to go about coding something like this ?

closed as too broad by Xander, Eric G, Gilles, schroeder, RoraΖ Apr 6 '15 at 11:29

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Can you clarify whether you're asking for something that will do this for a single computer you control, or for an entire network? – Xander Apr 3 '15 at 16:10
  • Are you concerned about accidental leaks or about malicious leaks? These are completely different scenarios. – Gilles Apr 3 '15 at 20:03
  • @Xander for a single computer. – Grim Reaper Apr 4 '15 at 2:37
  • @Gilles Accidental leaks being the data transmitted by email clients, chat software etc ? then yes, its intended for that. – Grim Reaper Apr 4 '15 at 2:39
  • Accidental as in an employee accidentally sends the customer list to joe@competitor.com instead of joe@yourcompany.com. Deliberate as in a disgruntled employee sends the customer list on wilileaks.org over a VPN that they installed for this purpose. – Gilles Apr 4 '15 at 13:21

What you're looking for is network data loss prevention.

There are some costly solutions from Code Green Networks, Symantec, etc. One free and GNU GPL-licensed ones is MyDLP (specifically you'll want the MyDLP-Network product) that does this.


You can use wireshark for sniffing packets and getting every kind of information from that.

Wireshark is opensource project
Check out its official page: https://www.wireshark.org/

  • Poor man's version of that network sniffer is at tcpdump.org – ott-- Apr 3 '15 at 20:33

Not the answer you're looking for? Browse other questions tagged or ask your own question.