Fcrackzip is a password cracking tool for ZIP files. Fcrackzip cracks the password by Brute-Force Attack or by a Dictionary Attack.
In a Brute-force Attack the attacker checks all the known combinations of passwords until the correct password founds.
Dictionary Attack involves providing a wordlist which contains a set of commonly used passwords.
$ sudo apt install fcrackzip
The general usage of fcrackzip for brute forcing the password is as follows.
$ fcrackzip -v -b -u <file_name.zip>
- -v for knowing what's going on in background. Commonly Know as verbose.
- -b for brute-forcing.
- -u for unzip.
- -p for setting the initial password for brute forcing or the file to supply password for dictionary attack.
- -D sets dictionary mode and reads passwords from a wordlist alphabetically.
The general usage for the dictionary attack is as follows.
$ fcrackzip -v -u -D -p <path_to_wordlist_file> <file_name.zip>
The common wordlist which is publicly available is rockyou.
Here is an example, using a dictionary attack. On opening the zip file, we found that the file was protected.
We used dictionary attack to find the password.
In this way cracking the zip is possible when you don't know the password.
For more information about the tool,
$ man fcrackzip