You do have an antivirus program, right?
In this category, there are two that receive equal mention.
First, AVG. Second, Avast!
I have personally used both and have no complaints. If you’re not running antivirus due to the cost of a commercial costs, run, don’t walk and install either one of these programs. And keep the virus definition database updated.
Also, remember to floss, and don’t run with scissors.