Let's say your wallet does get taken by malware but you have a backup copy. Could you recover and make the stolen one invalid somehow? What happens if there are two of the same wallets on the network? I would think both would become useless.
Send everything as soon as you got a chance to a safe account.
And by safe account understand "an addresses generated in another wallet file". That's because if you just ask from a new address from the backup, it will get from the pool of addresses that was already there, so the thief will have it too.