1. A computer implemented method comprising: prior to execution of a binary image of a portable executable file format: parsing, by a computing device, the binary image of the portable executable file format to generate a parsed field; determining, by the computing device, an attribute of the parsed field; comparing, by the computing device, the attribute of the parsed field to a valid characteristic of a valid corresponding field specified by a portable executable file format specification; determining, by the computing device, if the attribute of the parsed field matches the valid characteristic of the valid corresponding field specified by the portable executable file format specification, wherein determining if the attribute of the parsed field matches the valid characteristic of the valid corresponding field specified by the portable executable file format specification includes determining, by the computing device, if the attribute of the parsed field is valid for a predetermined operating system; identifying, by the computing device, if the parsed field does not match the valid characteristic of the valid corresponding field; and determining, by the computing device, a likelihood of modifying the parsed field that does not match the valid characteristic of the valid corresponding field to generate a valid field based upon, at least in part, one or more empirically determined rules, wherein the empirically determined rules are based upon, at least in part, possible errors that occur in the parsed field and a number of modifications to implement to correct each possible error.