One of the best free Malware, Spyware and antivirus available for free is windows Security. It comes fully installed with windows 10, powerful and fully free. You only need to update to get the latest spyware and malware filters to keep you more protected.
For third party advanced security, consider installing either Norton, Kaspersky, Avast, Bitdefender or Eset and get your one month free premium service. To extent your premium service, uninstall then re-install the app.