John the Ripper. It is a Password Cracking Tool, on an extremely fundamental level to break Unix passwords. Other than Unix-sort mixed passwords it also supports part Windows LM hashes and distinctive more with open source contributed patches. Now We are going to type the command to crack the password, so go ahead and type: john –format=raw-md5 /usr/share/wordlists/rockyou.txt.gz /root/Desktop/passw.txt; So what we are specifying the format for the password hash “md5” we can use like “SHA”, “SHA256” etc. But we chose do the md5. We Will Se the out put after entering the command.
Crack Facebook Password With John The Ripper blltly.com/1lmjh7. How-to - Cracking ZIP and RAR protected files with John the Ripper Updated: 2014-07-31 3 minute read After seeing how to compile John the Ripper to use all your computer's processors now we can use it for some tasks that may be useful to digital forensic investigators: getting around passwords. Today we will focus on cracking passwords for ZIP and RAR archive files. John the Ripper is a favourite password cracking tool of many pentesters. There is plenty of documentation about its command line options. I’ve encountered the following problems using John the Ripper. These are not problems with the tool itself, but inherent problems with pentesting and password cracking in general.
This post assumes you have access to a the target filesystem in question and want to extract and then crack the password hashes from the local machine.
In this example I am going to crack the account passwords used in Metasploitable 2 but the techniques here can be used in many different scenarios.
John the Ripper is included by default with Kali 2 – which is what I am using here.
To be able to crack the accounts we need two files from the target system:
- /etc/passwd -> Containing the user information
- /etc/shadow -> Containing the corresponding password hashes for the users
(Again there are various ways you could grab these files – for a vey simple example using Metaspolitable 2 as the target see this post here: https://securityaspirations.com/2017/07/03/metasploitable-2-compromise-nfs-shares/)
Once you have the two files we can begin cracking them with John the Ripper.
However before we give the hashes to John, we need to combine the two files into one so that the user and the password hashes are merged. We can do this with a utility called ‘Unshadow’ (also included in Kali2 by default).
The command required is:
unshadow Path_to_passwd Path_to_shadow > output.txt
Now we have the combined merged.txt file:
Now lets put john to work. We could supply a password list for John to use but it comes with a default set of passwords so we may as well try those first.
To start the crack, point John at our newly created file:
Within a couple of seconds we appear to have a hit on most of the accounts:
It’s not always this quick and of course we are still missing the ‘root’ account but you get the idea. I let the crack run for another hour before cancelling but the root account had still not being cracked. The password may be hidden in the John password list I would just need to let the cracking process run to completion to find out. If that failed it might be worth trying some bigger password lists (such as the ‘rockyou’ list).
One way or another, once complete, you can view each of the accounts and their corresponding passwords by running the following command and referencing the original file you gave John to crack:
john show <file.txt>
If you want to confirm they work, test them out on the Metasploitable box:
John Ripper is a fast password cracker currently available for many variants of Unix, macOS, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. In addition to the hash type of several crypt passwords most commonly found in various Unix codes, Kerberos / AFS and Windows LM hashes, as well as DES-based tripcodes and hundreds of additional hash and encryption versions in -jumbo.
In this article, we will now see how to crack and obtain a PDF password by attacking Brute Force with John The Ripper.
We will open Kali Terminal and extract the JohnTheRipper ('bleeding-jumbo' 1.8.0-Jumbo-1 based) source code from the repository in Github with the following command.
This version of Jumbo has Autoconf, which supports the very common chain that allows us to compile resources on a Unix-like system. When the compilation is finished, we move to the working directory inside the JohnTheRipper directory:
2 | cd./run |
If we want to see all the packages downloaded and welcome, we can use the code below.
In this series, we can see all packages of JohnTheRipper.
Now that we have the necessary tools, we can start the Brute Force attack.
Now we need to create the hash file of the PDF using the pdf2john.pl tool. This tool allows us to get the hash of the file with this Perl script, which can be extracted to a new file with the following command:
This uses UTF-8 as the default input encoding and starts guessing the password of the PDF file using the password list we created. Displays the password and path of the protected PDF, if found:
Crack Htpasswd John The Ripper Linux Command
I hope it was a useful article.