Is there a website or free downloadable program that allows a user to identify and remove multiple types of malware from an ISO file?
it could issue updates through fully functioning bitmap
So you're talking about stripping out steganography rather than neutralizing malware - in which case you'd get some mileage out of converting the file format (then possibly converting it back again). However it is technically possible to embed the content in such a way that it is still recoverable (IIRC the hidden WoW user id is extractable from a photo of the screen in addition to a direct image grab) e.g. if the image is of a barcode, then converting the format is not likely to disrupt the value embedded in the bar code.