Methods to determine the OS of the target system

I have mentioned in my previous article about why determining the OS of target's system is so important when attacking. In this article, I am going to tell you the methods that can be used to determine the OS of the target.

Generally there are many methods that can be used to accomplish this task. But we are just referring to the easiest methods. Operating system of a server can be found using :

• Linux command shell
• Online tools
• Search Engines
• And many more..

Linux command shell is a hard to implement now as you might not be having knowledge of Linux commands. (Also, I am posting articles on Linux system but commands are not posted yet.) So, for this time, we are just skipping the Linux coding part. The remaining two methods are easier to implement and here is a brief tutorial on it.

Using online tools such as Netcraft :

If you have read my previous post about finding the restricted URLs of a company, then you might be aware about netcraft. But if you aren't, don't worry. Here is the complete method :

1. Open https://www.netcraft.com/ in a new browser window.
2. Search the Home Page of netcraft for text 'What's that site running?'
3. You will find out a search box besides the text written 'Find out what technologies are powering any website'.
4. Type the name of the server you want to search for. E.g. www.microsoft.com (Here, im my case its ldce.ac.in).
5. Enjoy with the results.

Using Shodan search engine :

Ever heard about Shodan search engine..!! If you are new to it, make a practise of remembering this name as it becomes most useful in Hacking compared to Google. Also, Hackers refer it as the Most Dangerous Search Engine. To read more about it and learn how to hack using Shodan, click here.

Now, back to this article...Shodan search engine lets you to find specific computers (routers, servers, etc..) using a variety of filters. Follow these steps to find OS using shodan.

1. Visit : https://www.shodan.io/.
2. In the search box, type the website you want to search for. (See the image above, click on it to get full size view.)
3. Its Done..! Enjoy the results.

As you can see, Shodan gives you the extra results about the website's hosting server, the company providing the SSL certificate, etc. These are only the basics. Shodan can provide you a complete information about any server. But this part of the tutorial is limited. I have posted new article on Shodan Search Engine if you want to know more about it.