Where do you save the files (local drive / network drive / removable media)? Files are saved on the server under an Audit section.
Who has system permissions to view, modify, and delete those files? Myself (I am the Audit Dept.), the CFO, and the IT guy.
If saved on a network, how do you ensure that your data and files are backed up should your data and files be co-mingled with the other Bank backup data? During my IT audit, I verify that backups are being performed on the server. I personally don't have a problem with audit documents being stored on the bank's server. There are a lot of sensitive files there. HR files, Board Minutes, etc. Where else would you save them?
Do you know if the IT admin folks (or anyone else with elevated authority) have access to surreptitiously view, alter or delete the data? Yes, they do. However, you have to trust that they don't. I also have paper copies of most of the important things. It would be pretty obvious if something was changed. Also, I save some things in a pdf format, that can't be easily altered.
Do you digitally sign documents?
Do you think that someone is messing with your files?
You gain education by reading the fine print. You gain experience by not.