it is possible?
#1
Question 
I have a problems cracking my hashes according to the experts I have a md5 hashes and SHA256 hashes salted but, with unknown salts. Is it possible to bruteforce the salt to find out what is the salt if I know the plain text for some of my hashes?
#2
yes, it is.
#3
(05-02-2014, 11:07 PM)unix-ninja Wrote: yes, it is.

How!? I was thinking a dictionary atack for the salt value? or something like that
#4
You need to understand how mirrored hashes work.

For example, you have a sha512($pass.$salt) algorithm, so in order to brute force the salt you'd need to use sha512($salt.$pass), and configure the pseudosalt as the password.