Ugh..no it does not work that way.

You are thinking in hypotheticals like many developers do.

Most infostealer malware just exfiltratr your data and disappear before being detected do they can hit a lot of targets before commom av starts detecting them. People also accidentally disclose data, back it up on a usb drive and lose that drive, have their pc stolen,etc...

If you have keepass2 with a memory argon2 and a password/passphrase none of that is a concern.

Yes, the malware could also be a keylogger/RAT and you'd be screwed then. One the most important security mindsets to have is "perfection is the enemy of good", specific security controls exist to address specific threats/risk not to address arbitrary and and an unbounded number of possible threats.