View Single Post
  #5   (View Single Post)  
Old 17th February 2012
ocicat ocicat is offline
Administrator
 
Join Date: Apr 2008
Posts: 3,318
Default

Quote:
Originally Posted by daemonfowl View Post
in theory how can I deny nmap or any OS-detection tool to get the identity of my OS .. or at least to mislead it as to obtain wrong or more generic ID ..
I don't pretend to have the answer to your question, but fingerprinting is not a black-&-white subject. In fact, fingerprinting employs a number of heuristics which statistically identify the target -- which means that the result is not guaranteed to be correct.

The Nmap book has a section on OS detection:

http://nmap.org/book/osdetect-guess.html

...however, I will concur that it does not spell out the algorithms used in any detail. In many ways, the Nmap crowd doesn't want this to be widely known as OS developers will then modify their network stacks to return different results.

Ultimately, if you want a definitive answer, you will need to study the source code yourself.

Nevertheless, your question raises another in return. Why is it important to obscure what operating system you are running? In reading OpenBSD's mailing lists, there hasn't been that much discussion in over ten years:

http://marc.info/?l=openbsd-misc&w=2...erprinting&q=b

In general, believing that one can have security through obscurity is not an accepted best security practice.
Reply With Quote