When you just can't copy autorun.inf

I just ran into a weird problem while creating a bootable USB-stick, it was impossible to do a full copy of the files from an .iso. I tried robocopy, xcopy, and even resorted to a file copy through the file explorer. Robocopy consistently reported the following error though:

2015/10/01 17:10:49 ERROR 5 (0x00000005) Copying File g:\autorun.inf
Access is denied.

It turned out that the antivirus software was blocking the file copy, without notification. Disabling the antivirus protection temporarily let me copy the files without issues. I'll leave this here, in case there are other poor souls out there on the Internet with the same issue.