The best anti-malware prevention is the finger you use to left-click your mouse. The safest key on your keybpard is ESC and is much more powerful than hoping for an Undo feature.
Hyperlinks : Risky Business
One of the easiest ways to get infected is through a little mouse-click. Be prudent as you consider clicking a link on a webpage or in an email. Does the link direct you off of the original domain you accessed or the one with which you are familiar? If the link is in an email, do you know the sender? Did you request this message and/or content? Anti-malware software can help protect us, but we are still driving and we are in control of our destiny. Ask yourself: "Do I need to follow this link? Is there any risk? Is this PC mission-critical?"