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theflamer14
November 2nd, 2008, 17:29
Hi,

I've been trying for about 2 weeks to open my pdf files which contain a work project. Unfortunately, I've forgotten my passwords for them, and now I can't seem to find any software that recovers my passwords. It'll take forever to brute force it becuase the lengths of the passwords were about 10 or 12 characters. Is there anyway to bypass/remove the passwords with Olly? Any help is appreciated.

Darkelf
November 4th, 2008, 12:19
I'm not sure if you serious with that, because a pdf-file is by no means an executable - so what do you want to do with a debugger here?
I have no idea how a pdf is crypted or obfuscated or whatever, but a disassembler is in any case the weapon of choice.

Best regards
darkelf

Patrickssj6
November 4th, 2008, 15:12
I don't know how PDF files are encrypted but I'm pretty sure it's similar how ZIP or RAR files are packed with passwords.

There is no comparison if the entered password is valid or not. The password is needed for the decrypting process.

If you want to unpack a packed archive file, the entered password is part of the decrypting process. In the end a CRC32 check is made if the unpacked file is valid or not. If it's not the password was wrong or there was an error while packing/unpacking.

Darren
November 8th, 2008, 22:37
I believe this product is one of the better ones

http://www.elcomsoft.com/apdfpr.html

But i guess its gonna depends on encryption method used, if your going to be able to recover it or its gonna be a case of a slow bruteforce attack

Not the same thing, but in a similar area

http://securityxploded.com/firemaster.php

Uses a method if you can remember part of your password