some you can trust
First, if you are running multiple anti-virus/malware clients you are either much too paranoid or much too easily swayed by those that sell such things. There is an industry that does quite well by keeping consumers scared. Beyond that, you have to make certain choices with software, just like with the rest of your life. Be brave! You can trust updates from MS, Oracle and Adobe in my humble opinion. There are others too, I am sure. If something comes your way via an automatic updater that is part of a legitimate installation of software, trust it. On the other hand, if you get offers for much of anything from unsolicited sources ignore it. In that case, the odds are very much against you. One other point: I have never seen one 'pop up' during an internet session that is worthy of my consideration, another fact of life. On the other hand, you can just stay scared and paranoid and buy all sorts of things that enrich others and don't do you much good. Like I said: choices.