Quote from: Ambatman on November 17, 2024, 10:37:17 PM

If you don't mind me asking who's the owner of the PDF?
How are you sure that it's a combination of 8 characters and not 12?
Since you brute forcing, You just have to keep going and maybe consider that the password might be complex or Longer.
I think there are app for cracking PDFs but usually for one's with simple password.

The owner of the PDF is a client of my, he had an account with an exchange called aximetria, this exchange went bankrupt and sent him the encrypted PDF. He received the password via SMS on his cell phone, but he no longer has the number and has never seen it. I don't know how many characters the password is, I tried 1-8 characters at random with all the combinations according to my program and the hardware I have. Above 8 characters, for example 9 characters, all combinations are impossible to test. Also because the password can be more than 20 characters long. The strange thing is that usually passwords in pdfs are much simpler, as you said.