Why do I keep getting a Trojan Virus from YAHOO?

this is my 2nd time in a month i've picked up 7 trojans from yahoo MB's!! what can i do to prevent this i know an easy answer would be stop going on the MB's, but c'mon i'm not downloading anything or clicking on any ads. I have anti malware bytes so removing them is easy enough, but its becoming a nuisance to unhide everything and what not. For some reason i cant find the logs so i cant tell you exactly what virus im getting hit with. I guess my question would be is there a better firewall or something to block this crap or do i have to just keep waiting till im infected