Again: an ISO is different. A right click scan will not scan the contents of an ISO. It will just scan the ISO as a file itself, which at default settings is just a quick pass. Looking at the header and such. So neither the resident scanner nor a on-demand scan will do an in-depth scan of the ISO. Mounting the ISO however, and then scanning the mounted folder/drive, will result in scan of the actual contents. Which typically is program data with lots of executables.
My point is that either you set the resident scanner to scan every bit of every file downloaded or accessed, and massively slow down the PC, or … leave the resident scanner at the default sane settings, and be aware it will most definitely miss things. So don’t rely on the resident scanner as a catch all gatekeeper. Which brings us back to my initial observation of: there are a very real use cases for the on-demand scanner over the resident scanner. And even then you have to use it in the right way. It is just one of those exceptions I mentioned.
