fcrackzip

29 Oct 2022 - GRX6

fcrackzip is a very nice tool to crack password protected files using dictionaries and brute force.

To install we just need to run apt (for Ubuntu/Debian).

$ sudo apt install fcrackzip

To test how it works let’s create a zip file with our flag.

$ sudo zip --password abc123 file.zip Desktop/user.txt

Then, let’s try to break it up using a dictionary.

$ fcrackzip -D -p /usr/share/john/password.lst -u -v -c 'a1' file.zip
found file 'Desktop/user.txt', (size cp/uc     53/    41, flags 9, chk 66d3)


PASSWORD FOUND!!!!: pw == abc123

Brute force is also effective in this case.

$ fcrackzip -b -l 1-6 -u -v -c 'aA1!' file.zip     
found file 'Desktop/user.txt', (size cp/uc     53/    41, flags 9, chk 66d3)
checking pw aavpv1                                  

PASSWORD FOUND!!!!: pw == abc123