Malwarebytes has a free version for anti-malware that I would recommend you to use. If you need the premium features and run on multiple devices, they have package starting from $39 (around that, I don't remember the exact number). There is other good software such as Avira, Avast, you can have a look. However for me, it's best is to arm yourselves with more knowledge about malware before choosing your provider, including malware types, how to recognize them and what to do when they attack. I believe you then can push the software to its best performance. Hope it helps!