On most Unix systems passwords are stored in the
This means using the Unix echo out command, cat, you can see the contents of this file:
The passwords will be encrypted, but unfortunately quite insecurely. But the encryption has long been crackable. A tool called John has long been availble. It runs in dos, and you can crack the average unix password in a couple of hours. A password shorter then four letters takes no time at all (make sure no passwords are this long).
These programs work by eithey trying every single possiblity, one by one, or using a dictionary of possible passwords.
On most Unix systems now, the passwd files is “shadowed”, though on some poorly set up systems merely typing “locate shadow” will find the file for you.
You can see if the passwords are shadowed because in etc/passwd there will just be * where passwords should be.