[HELP] grunge brushes [where to download]

Ok, i have been using photoshop for quite some time now and im starting to get pretty good at it (one of my best pieces is my current signature. I have not downloaded any new brushes in a while so i need some help finds legit sites that have them, i dont wanna have to pay. I downloaded some yesturday and they had a trojan, gf 2hours of fixing. SO where are some places where i can find some nice decent ones.

p.s. i currently only have the default ones because i got a new computer

 

deviantart.com is good i hear,i havent photoshopped in awhile and i forget how to add new brushes though lol