The fact that some specific anti virus can detect it, it's no longer a secret who also manufacture these viruses. But anyway, if antivirus won't be enough to detect these malwares.
I agree that there are a couple of good antiviruses out there but nonetheless, you can't rely on them plus it's not even advisable to rely on them. Your personal carefulness and cyber information are some of the most important things that keep you safe from malwares and viruses. People are often quick to download cracked apps which can be closed source most times and grant random permissions very easily to skip installation prompts.
It's very possible to download a malware thinking you installed an antivirus without your knowledge if you are not careful and informed enough.
In my personal experience, I've downloaded a lot of them when I was ignorant of the dangers of these crack apps from pirated websites. It's dangerous and now that we're in crypto and we are using our personal computers/devices to access also our bank accounts. We should be more careful than before. If we're earning already and we can avail to buy the software that we have to use, subscribe to them and pay the amount because it's also a help to the developers of it and the same goes if you want to avail some anti virus. If you think it helps you, do it as long as you pay them.