The same guy who made me worried a while ago has brung a new fear.
He leeches off my family, uses my younger brother and he has a clear hatred against me. He probably has criminal contacts, thus making me worried and he's clearly in a risk group to fall into drug addictions.
I don't want that fuck being around my family. He's bringing us down, he's a risk regarding disease and he's may bring my brother down completely in the future.

I would suggest that you confront him about his background and how he views you. Talk to him. Get a clear, straightforward talk with him one-on-one. I would also suggest talking to your brother about how you feel, and that your brother should also be aware of who his friend actually is. Don't take a drastic, crazy action. Try to cut the guy loose easily and make sure that your brother understands why. Tell your family about how you feel as well. Chances are, someone might feel the same uneasiness about your brother's friend.

Good luck.

Muahahaha. Give him the talk ..... My talk would go a little like this ...

First catch him preoccupied and alone

" ahem. Hey you ass hole Ya you ain't nobody else around you f"&%kin idiot just what the f(&@ you think your doing here ? Hmmmm?
You think your f&%+ing sly or something you sneak thieving junkie mother f&@#er I don't like you hanging around my friends and family so here's what's gonna happen I'm gonna turn around in a circle and by the time I come back around your gonna be gone and if you ain't I'll go Wolfe on your ass and use my manimal ferocity to rip your f&%+ing face off and I'll mark that s&#t by pissing all over you yougot that you god damn f$&#ing flake"

Then glare at him like he's the one thing you would absolutely not put up with for another second ....

And make sure you find some dirt on him first don't do stuff like that to nice ppl ok only the rotten ones

Don't follow >>3 advice. That just makes you seem like the aggressor, which can put you in a very bad situation with your family, and give the guy an upperhand. Be reasonable. Think logically and talk it out. Simply just ask if you can talk with him, like, "Hey, dude, could we talk for a second?" It's much better to be the non-aggressor because then if he flips out, he's the one who seems unreasonable.

I agree With Choko even if there are CCTV cameras around put up your hands like your trying to calm him down even if you are trying to provoke him so that he looks like the aggressor