How to crack User Password?

Crack other user password is not difficult, it’s just another interesting stuff to do. What you need is
you must have access to another person computer who’s using linux, once you get the shadow file, you can see the password in plain text.

Shadow File is a File in which password hash is located.

/etc/passwd


/etc/shadow

you can crack them all and see the password in PLAIN text.

John The Ripper

John The Ripper is a tool that specially created for password cracking purpose.

How to Crack User Password?

1. Steal Password File

Inside the Password File, there are password hashes of all users in that computer.
The password Hashes will be in MD5 Format (For Ubuntu Hardy and below) and SHA Format (For Ubuntu Jaunty and Karmic)

There are tons of ways to steal the password file, but I will support with my way.

scp [username]@[IP]:/etc/passwd ~/Desktop/


scp [username]@[IP]:/etc/passwd ~/Desktop/


That code will make copies of the password file from the victim computer to your desktop.

2. John The Ripper in Action


cd ~/Desktop


sudo john --show


And that will show all EASY passwords but if you stiill don’t get what you want, you will want John The Ripper to work more for you.


sudo john


That will make John The Ripper do some attacks to the file.

If you are lucky enough, your attack will last a few seconds, but if the password is veryyy strong, it can take weeks.