Adblock = kinda antivirus thing, it blocks all the malware that sometimes gets to show as ads. If some asshole fucker tries to push malware in some ad it gets blocked. Have you seen some ads on shady sites? You DO NOT want to even view them, you never know what you may catch. Ads are third party content and i never trust third party. Noscript+ublock+canvas blocker. You don't need antivirus if you can't be infected.