How to protect your Private Key file & Wallet file on Desktop Wallets? Eg. ones like Electrum, Exodus, Jaxx, Copay? So that if a hacker or malware tries to get access to it. How to know which file it is in the Wallet directory?
The best protection is always to have your important files on a computer that is entirely disconnected from the internet, so malware has almost no chances of getting your keys.
Also make sure to do regular backups, because a failing hdd can be also as disastrous as a malware infection.
The wallet file depends on your wallet software. Just google it. For Core, it would be wallet.dat.