password cracking

Before we get into cracking passwords with programs, I will explain a couple old-fashioned ways to obtain someone’s password.
 
• Social Engineering – Social engineering is when a hacker takes advantage of trusting human beings to get information from them. For example, if the hacker was trying to get the password for a co-workers computer, he (Even though I use “he”, hackers are of both genders, and I just chose to use “he” in these examples.) could call the co-worker pretending to be from the IT department. The conversation could be something like:
                         "Bob- “Hello Suzy. My name is Bob and I’m from the IT department. We are currently attempting to install a new security update on your computer, but we can’t seem to connect to the user database and extract your user information. Would you mind helping me out and letting me know your password before my boss starts breathing down my neck? It’s one of those days, ya’ know?”
                            Suzy would probably feel bad for Bob and let him know her password without any hesitation. BAM! She got social engineered. Now the hacker can do whatever he pleases with her account.\

• Shoulder surfing – Shoulder surfing is exactly what it sounds like. The hacker would simply attempt to look over your shoulder as you type in your password. The hacker may also watch weather you glance around your desk, looking for a written reminder or the written password itself.

• Guessing – If you use a weak password, a hacker could simple guess it by using the information he knows about you. Some examples of this are: date of birth, phone number, favorite pet, and other simple things like these.

Now that we have the simple low-tech password cracking techniques out of the way, let’s explore some high-tech techniques.
                                                     DICTIONARY ATTACKS 

A dictionary attack is when a text file full of commonly used passwords, or a list of every word from the dictionary is used against a password database. Strong passwords usually aren’t vulnerable to this kind of attack. In the following example, I will use Brutus, a very common password cracker, to show a dictionary attack against an ftp server. Brutus is a Windows only program, but at the end of this chapter I will list a couple more password crackers, some of which are made for Mac, Windows, and Linux.