This involves the recreation of a system by the hacker in an attempt to find a vulnerability. Through fuzzing, hackers can determine all the safety precautions that system developers have to put into consideration and the types of bugs that they had to fix while making the system. An attacker also has a higher chance of creating a vulnerability that can be successfully used against modules of the target system. This process is effective since a hacker gains a full understanding of the working of a system, as well as where and how it can be compromised. However, it is often too cumbersome to use, especially when dealing with large programs.