‫So in the previous lecture, we couldn't crack the password of the user cyber lab, so let's try to
‫crack it with the brute force attack, brute force attack means a lot of time because it tries all the
‫possibilities.
‫So if you choose the correct character set, the success rate of cracking a password by brute force
‫attack is theoretically 100 percent.
‫But how long will it take if the password length is more than eight?
‫It will take months, years or thousands of years to try all the password possibilities for any ordinary
‫computer.
‫So as you see in the table, the L.M. password is not empty for Cyber Lab.
‫A tip here, the hash of an empty password starts with a D and ends with four E.
‫Look at the elements of the guest user, split the hash into two identical parts, you'll see two hashes
‫that start with add and end with four easy.
‫As I mentioned before, the method splits the password into two seven character passwords and then takes
‫the hash, which means we have to crack to seven character passwords.
‫Well, fair enough.
‫Method converts the password to all caps, so the character set is not so big.
‫We can crack and L.M. hash in an acceptable time interval, so right, click on the Cyber Lavalin and
‫brute force attack Selek L.M. HaShas.
‫The brute force attack window is a bit different from the dictionary attack window, as expected, no
‫dictionary list now.
‫Instead, we have a character set combo box.
‫The default character set are just uppercase letters and numbers, no alphanumeric characters in the
‫set.
‫So to keep the demo fast, let's just go with this set.
‫It says to hashas loaded, as you know, the hash value is split into two identical parts.
‫On the upper right hand corner, we can choose the minimum and the maximum length of the passwords for
‫limited max length for the password is seven.
‫So this configuration is perfect.
‫Now, I pressed the start button to start the attack.
‫Wow, it found the value of one of the hashes in milliseconds, so let's look at the hash file.
‫Yeah, it's the second part.
‫So that means that the password ends with Q.
‫I think the password of a cyber lab user is the same with the passwords of the administrator except
‫the dot at the end.
‫But we'll see.
‫So let's look at the key Keurig.
‫Cain tries more than 10 million passwords in a second.
‫Now, that's pretty fast.
‫In the time left frame, we can see that the trying all possible passwords will take about two hours
‫unless Cain cracks it.
‫So let the Cain run for a while.
‫All right, and we're back.
‫It took more than an hour and here's the result we're lucky because no alphanumeric character is in
‫the password and we succeeded to crack it.
‫The first part is one, two, three, four, QQQ.