Not sure if this is a dumb question or if this is a well-established technique, but are there any firewall/UTM solutions that perform a default sanitization of incoming files such as jpg, doc, pdf. I don't want to operate extensive blocking lists or rely on signatures. I'd be thinking about having the firewall execute an automatic jpg -> tiff -> jpg conversion (just as one example), which would have the effect of stripping many of the nasties that get delivered that way. Is this possible?
I'm not sure that a firewall would be the best tool for the job. That would add a lot of code to the firewall, much of which would already exist in the default handlers for each file type. You might consider using scripts that use the default or separate handlers in a sandbox to perform the conversions.
I'm not aware of anything like that- it'd have to be the world's greatest file converter ever made (in the sense of supported file types, optimization for hardware and conversion ease) and even then it'd hog resources to bog down even somewhat fast machines depending on the workload.
Those are closest to what OP mentioned. Symantec Disarm Technology and Sakimori are closest. Originally mentioned here.
These only work on e-mail as best as I can determine and are directed to commercial e-mail server environments. Not on direct downloaded files from the Internet.
