JPG Files, injected with malicious code - What will happen when Unity tries to load them?

So that's the (purely theoretical, mind you) question.

If I injected some kind of malware into a jpg file and Unity loaded it through the WWW class, would the code actually execute? The plan is to load custom skins from any source the user offers, but if the same user would be able to hijack other players' computers using our game, it'd be dreadful.

Any idea?