One must have a regular maintenance routine for their PC and part of this is regular scans for Viruses and Malware.
There is not any one Antivirus or Malware software that is going to give you a 100% protection, but for the most part most of them are pretty accurate.
Choose a Antivirus program to be your main.
I would recommend Avira.
Choose a Malware Program to be your main.
I would recommend Malwarebytes' Anti-Malware.
With that being said, it's always a good idea to double check your PC by using alternative software every once in awhile just to make sure that the system stays clean. This can be done by using online scanners.
One must use vigilance and don't get to worked up over it.