PDFCrack is a GNU/Linux open source (GPL) PDF password cracker for recovering passwords and content from PDF files which have been locked and protected with lost or forgotten password. PDFCrack is command line driven without any external dependencies, and use guessing or password cracking method of dictionary attack and brute force attack. PDF Crack supports and works on Linux and other POSIX-compatible systems, and a Windows binary version has also been ported and compiled with Cygwin, a Linux-like environment for Windows.
Features of PDFCrack
- Supports the standard security handler (revision 2, 3, and 4) on all known PDF-versions.
- Supports cracking both owner passwords and userpasswords.
- Both wordlists and bruteforcing the password is supported.
- Simple permutations (currently only trying first character as Upper Case).
- Save/Load a running job.
- Simple benchmarking.
- Optimized search for owner-password when user-password is known.
Usage Syntax for PDFCrack
To use PDFCrack, open a command prompt window, and run pdfcrack or pdfcrack.exe to list out all options available. The default command syntax is as follow:
pdfcrack -f filename OPTIONS
Any options is optional, and not necessary require. So to use PDFCrack to recover and crack owner password or user password of a PDF files, simply enter the following example command:
pdfcrack -f locked.pdf
Replace locked.pdf with the actual filename for the protected PDF files which you have forgot the password. To speed up the cracking process, specific minimum (-n) and maximum (-m) length for possible password, and specify the possible characters (-c) to brute force the password.
What PDFCrack cannot do?
Using the software, you cannot change/override/remove the copy/print/etc. restrictions of the PDF document. If you want to recover a document you can recover the owner-password and then use another tool for decrypting and/or changing the permissions. PDFCrack is a tool for recovering the information with the owners consent, not overriding the allowed usage.
Developer’s website: http://pdfcrack.sourceforge.net/
Direct Download: http://sourceforge.net/projects/pdfcrack/files/