Read Me Run Me First Backup notice

Hi guys.

I'm about to start the Read Me Run Me First guide but have read the notice at the very begining about doing a backup to protect my important documents. Would you mind though telling me if this is a good idea if I suspect there is malware on my system? I mean, I think there is and that is why I want to follow the steps in your above guide, but if I do a backup and there is malwhere on my system, and I need to install that backp onto my system won't I be reinstalling the malware back onto my system?

Just trying to figure out if doing a backup before starting the above is a good idea. Sorry if the answer sounds obvious. Pretty much a novice here.

Thanks