Need help with Mac OS High Sierra

Hi, I'm trying to run Mac OS through virtualbox, and I'm using High Sierra to do it, but the iso I had for it gives me the damage error, and I know my time is right, so I don't know what the issue is. I would like to just redownload the installer, but I don't have any access to a mac to do so. A friend of mine is too scared to let me use his (he's paranoid), and nobody else I know has a mac. Would anyone be willing to give me a High Sierra ISO fresh from the Apple Store. I'd be very grateful, thanks.

Author: @cyph3r-8800