You need an anti-malware program to protect the one thing malware is trying to get from your computer … your money.
Simple Malware infections allow more severe infections to attack your computer.
A system that is running slower than usual is symptomatic of Malware infection.
Malware is easy to get if you are connected to the Internet and using a standard Internet browser. Websites that offer perks, often contain backend PUPs ( Potentially Unwanted Programs). These programs slow your computer down and create a possibility of clicking on something you do not want in an effort to get the computer to do what you do want. What can happen then is you will accumulate other forms of Malware such as Adware and Spyware.
Adware is the vehicle for you receiving pop-ups and ads for things for have already searched for on the Internet. Have you ever wondered why you see certain ads on the sidebar of your Yahoo page? Adware is helping that. Spyware does that to a higher level. It actually feeds the originator of the Spyware with information about your browsing history by spying on your surfing. These two Malware types slow down your system too.
I have found that a computer that is routinely cleaned with a program like Malwarebytes, does not get the more extreme and harmful Malware (trojans, bots and worms). The cleaner your browsing history and temporary files are, the safer your Internet surfing will be.