Hi @XhenEd some types of malwares can infect also the host OS, obviuously this happens only with the more dangerous malwares, infact also with the VM we aren't completely secured. Anyway if you only use the VMs for scan malwares, to testing Antivirus products you can do it, but pay attention if you want to run them, because even if you are in a virtual machine the risk of an host os infection can be also high.Update!
Added: Virtualbox as my VM software
I'm planning on testing some AVs (or any softwares) within VM against malwares. What do you suggest that I should do for precautions? From what I understood, VMs are pretty much secured. But according to my research, there might be vulnerabilities within VM that might expose the Host OS.
I'm not an expert on cyber-security, so what I'm just gonna do is to scan the malwares with AVs. If the malwares aren't detected, then I will run them. Is this okay? I have snapshots in place. What I'm afraid of is that there might be malwares that might infect the Host OS. However, my Host OS has the security configuration that I think is enough to stop any malware from running. So, what can you suggest?
Especially if you want to test malwares, which can connect to malicious hosts or IPs, it could be very dangerous in some cases because the malware can infect the host OS through the internet connection.
In addition if you want to start Malware Analysis you can do it in a Virtual Machine, but it is better to do only static analysis, because the dynamic analysis can infects the real system.
Anyway good addition, thanks for sharing