Why I have Malwarebytes Anti-malware

"Spigot" is one of those very devious bloatware installers that switch your default Search provider to Yahoo and installs itself and several other nasty little programs into your Username\Appdata\Roaming folder, where you ordinarily may not be tempted to look for unwanted nasties. Malwarebytes finds things like this that your regular anti-virus (read: Avast Internet Security) misses. And this is why I have it. As they tell you, this isn't anti-virus - it complements anti-virus by finding what that misses. And it really works. Don't go surfing without it.