Extensions of encrypted files: https://fileinfo.com/filetypes/encoded

To find common encrypted files:

for ext in $(echo ".xls .xls* .xltx .od* .doc .doc* .pdf .pot .pot* .pp*");do echo -e "\\nFile extension: " $ext; find / -name *$ext 2>/dev/null | grep -v "lib\\|fonts\\|share\\|core" ;done

To find all ‘to John’ modules:

locate *2john*

Encrypted SSH key to John:

ssh2john.py SSH.private > ssh.hash

Encrypted PDF to John:

office2john.py Protected.docx > protected-docx.hash

Writeup

Download the attached ZIP archive (cracking-protected-files.zip), and crack the file within. What is the password?

office2john file.xlsx > hash

john hash -w rockyou.txt