1. A computer-implemented method, comprising: identifying a plurality of strings in a document that includes source code of at least a portion of a software module, the source code described in a programming language, the identifying of the plurality of strings comprising searching the document for individual ones of the plurality of strings that are delimited by one or more string delimiter characters designated by the programming language; determining an information entropy associated with the individual ones of the plurality of strings; incorporating the individual ones of the plurality of strings with the information entropy at least equal to a threshold information entropy into a dictionary; during execution of the software module, performing a dictionary attack on one or more secure features of the software module using the dictionary, the dictionary attack including providing one or more strings of the plurality of strings as a set of test credentials for requesting access to the one or more secure features; determining that the providing of the one or more strings enables the access to the one or more secure features of the software module; designating the one or more strings as one or more credentials written into the source code; and sending a notification describing the one or more credentials written into the source code.