If you have a lot of coins - get a Nano Ledger S and use it with MEW. This way the private key is never even transferred from Nano Ledger on to the computer or the internet.

The security around Nano Ledger S is insane - the integrity of the firmware is checked every time you log in thru their apps - and also by protective chip that does the same check each time it starts up.

Hacking it would require to reverse engineer it, design an extra chip to take out the integrity check and somehow sneak it into the device. They even post a video on their site how to physically check the chip set.

With this hardware wallet you can use any computer, even an infected one with no risk. Would have detected this type of scam in a heart beat.