In this tutorial we will be using the Crunch Password list generation tool in Kali Linux. Crunch is an easy to use tool for generating a custom made password list used for brute force password cracking. Crunch comes as a standard tool in Kali Linux. This tutorial shows you how easy it is to generate a password list containing all combinations of 4 letters, 5 letters and a password list containing 5 letters followed by a year. You can also use Crunch to generate password lists based on default router passwords as demonstrated in a few other tutorials. UPC Broadband routers use 8 capital letters as default password for Wifi and TP Link routers use the 8 digit default WPS PIN. Both can be easily generated with Crunch.
Crunch password list generation
Let’s use the following command to have Crunch generate a wordlist containing all combinations of 4 letters:crunch 4 4 ABCDEFGHIJKLMNOPQRSTUVWXYZ -o /root/Desktop/wordlist.txt
The generated Crunch password list has a size of 2 MB
Let’s use the following command to have Crunch generate a wordlist containing all combinations of 5 letters:
crunch 5 5 ABCDEFGHIJKLMNOPQRSTUVWXYZ -o /root/Desktop/wordlist.txt
The generated Crunch password list has a size of only 67 MB
The next wordlist we are going to make is a wordlist containing all possible combinations with 5 letters follow by 1980. The 1980 represents a year of birth for instance, commonly used as a password in combination with a name:
crunch 8 8 ABCDEFGHIJKLMNOPQRSTUVWXYZ
-t @@@@1980 -o /root/Desktop/wordlist.txt
The generated Crunch password list has a size of only 3 MB.