Crack .pdf password

BroodsSexton

Member
SoSH Member
Feb 4, 2006
12,630
guam
I have a document that's several years old (maybe 4 or 5) and has a password on it to prevent it from being opened. Any bright ideas on how to crack it?
 

cgori

Member
SoSH Member
Oct 2, 2004
4,006
SF, CA
https://www.quora.com/How-can-I-open-a-PDF-file-which-is-password-protected-and-I-have-forgotten-the-password

It appears that much older PDF files, v1.3 and down are sort of trivial to hack. 2.0 and up use "real" cryptography, and I think 4-5 years ago you'd likely have a v2.0 PDF (you can look at "document properties" on a mac, and probably something similar on a PC to find the version: https://blog.idrsolutions.com/2010/09/how-do-i-find-out-the-pdf-version-used/ )

There may be some free/demoware things mentioned in that quora that can create a non-password-protected PDF from a protected one, but I suspect they depend on it being the older version. If they are free you might give them a shot.

If it's a new PDF and a strong, unknown password you are pretty screwed, I'm sad to say.