How to Crack Passwords with John the Ripper in Kali Linux

Install John the Ripper

John the Ripper is a powerful password cracking tool that can be used to crack passwords in Kali Linux. To install John the Ripper, open a terminal window and type the following command: sudo apt-get install john. This will install the John the Ripper package on your system. Once the installation is complete, you can start using John the Ripper to crack passwords.

John the Ripper is a powerful tool that can be used to crack passwords in Kali Linux. It is a free and open source tool that can be used to crack passwords in a variety of ways. It is a command line tool that can be used to crack passwords using a variety of methods, including dictionary attacks, brute force attacks, and rainbow tables. It is a powerful tool that can be used to crack passwords quickly and efficiently.

Download the Password File

In this step, we will learn how to download the password file that we will use to crack the passwords with John the Ripper in Kali Linux. To do this, we will need to use the wget command. This command will allow us to download the file from a remote server. To use the wget command, we will need to provide the URL of the file that we want to download. For example, if we wanted to download a file from https://example.com/password.txt, we would use the following command:

wget https://example.com/password.txt

Once the file has been downloaded, we can move on to the next step, which is to run John the Ripper on the password file.

Run John the Ripper

In this step, we will learn how to run John the Ripper in Kali Linux to crack passwords. First, open a terminal window and navigate to the directory where you have installed John the Ripper. Then, type the following command to run John the Ripper:

john --wordlist=password.lst --rules --stdout > cracked.txt

This command will use the password list file (password.lst) to crack the passwords and output the results to a file called cracked.txt. The --rules option tells John the Ripper to use the built-in rules to try to crack the passwords. This can significantly increase the chances of cracking the passwords.

Once the command has finished running, you can view the results by opening the cracked.txt file in a text editor. The file will contain a list of cracked passwords and the corresponding usernames. You can then use this information to change the passwords of the users.

View the Results

Once you have run John the Ripper, you can view the results. To do this, type john --show [name of the file] in the terminal. This will show you the cracked passwords in the file. You can also use the john --show --format=raw-md5 [name of the file] command to view the passwords in MD5 format.
If you want to view the cracked passwords in a more readable format, you can use the john --show --format=raw-sha1 [name of the file] command. This will show you the passwords in SHA1 format.
You can also use the john --show --format=raw-sha256 [name of the file] command to view the passwords in SHA256 format.
If you want to view the cracked passwords in a more detailed format, you can use the john --show --format=raw-sha512 [name of the file] command. This will show you the passwords in SHA512 format.
You can also use the john --show --format=raw-nt [name of the file] command to view the passwords in NT format.
You can also use the john --show --format=raw-des [name of the file] command to view the passwords in DES format.
You can also use the john --show --format=raw-md4 [name of the file] command to view the passwords in MD4 format.
You can also use the john --show --format=raw-md5-gen [name of the file] command to view the passwords in MD5-GEN format.
You can also use the john --show --format=raw-md5-gen-salted [name of the file] command to view the passwords in MD5-GEN-SALTED format.
You can also use the john --show --format=raw-md5-gen-salted-sha1 [name of the file] command to view the passwords in MD5-GEN-SALTED-SHA1 format.
You can also use the john --show --format=raw-md5-gen-salted-sha256 [name of the file] command to view the passwords in MD5-GEN-SALTED-SHA256 format.
You can also use the john --show --format=raw-md5-gen-salted-sha512 [name of the file] command to view the passwords in MD5-GEN-SALTED-SHA512 format.
You can also use the john --show --format=raw-md5-gen-salted-nt [name of the file] command to view the passwords in MD5-GEN-SALTED-NT format.
You can also use the john --show --format=raw-md5-gen-salted-des [name of the file] command to view the passwords in MD5-GEN-SALTED-DES format.
You can also use the john --show --format=raw-md5-gen-salted-md4 [name of the file] command to view the passwords in MD5-GEN-SALTED-MD4 format.
Once you have viewed the cracked passwords, you can then proceed to the next step which is to change the password.

Change the Password

Once you have cracked the password with John the Ripper, you can change the password to something more secure. To do this, you will need to use the passwd command. This command will allow you to change the password for the user you are currently logged in as. To change the password, open a terminal window and type the following command:

passwd

You will then be prompted to enter the new password twice. Once you have entered the new password, the password will be changed. It is important to note that the new password must meet the system's password requirements. For example, some systems may require that the password is at least 8 characters long and contains at least one number. Once the password has been changed, you can log in with the new password.

It is also important to note that you should never use the same password for multiple accounts. This is because if one account is compromised, all of your accounts are at risk. To ensure that your accounts are secure, you should use a different password for each account. You can use a password manager such as LastPass to help you generate and store secure passwords.

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