Wa'alaikum Assalam wa rahmatallahi wa barakatuhu
Mashallah, nice to see a serbian on the forums! (:
My dear brother, read this.
http://islamqa.info/en/ref/93031/buy...thing%20stolen
If you know who the processor was stolen from, the best thing to do is tell the person who sold it to you to repent, and to give the money you made back to the person it was stolen from. Since you didn't know it was stolen, inshallah you will not be punished for it, but if you can give give the money back to the person it was stolen from then you should inshallah.
fi aman Allah
w'salaam