Nope. I never give out hacked Pokemon on the GTS. I have a couple that were traded to me by friends, but they're my burdon and I have no right to dump hacks on somebody else that I don't even know. (For my friends who want hacked Pokemon, now, that's a different story).
Mainly, I don't trade hacks or bad Pokemon over the GTS because, of all the GTS trades I've done, I always get an honest, legit Pokemon that's exactly what I wanted. Once, I got a Lv.100 Rayquaza with Pokerus in exchange for a Lv.1 Feebas that I'd hatched from an egg. I believe the OT was Oren or something of that sort. Whoever he is, he's my friend.