It does look eye-catching right? Cracking PDF password in Ubuntu. I posted this because sometimes I got pissed off when I need to open important PDF files and forgot the magic words. Here I will show you how to crack it and remove that password for good.This is the simple way to crack it:
Simply open your terminal and type these following codes:
sudo apt-get install context
Afterward, I would recommend you to rename your PDF file into something easy to remember like abc.pdf
Then input these following codes:
pdftops protected.pdf abc.ps
pstopdf abc.ps abc.pdf
Congratulation, now you have cracked your PDF file 
i got error, “Error: Incorrect password”
Not work with my pdf in Kubuntu 10.04
pdftops protected.pdf abc.ps say “Error: Incorrect password”
ERROR !!!!
this is a lie !!!
Error: Couldn’t find the ‘EBX_HANDLER’ security handler