n essence, I created a text file containing just “hello” and asked the fuzzer to keep feeding it to a program that expects a JPEG image… Such a fuzzing run would be normally completely pointless: there is essentially no chance that a “hello” could be ever turned into a valid JPEG by a traditional, format-agnostic fuzzer, since the probability that dozens of random tweaks would align just right is astronomically low. - Pulling JPEGs out of thin air