Find overriden native objects

01_Readme.md

The goal of this code is to find javascript native objects which have been overriden (by various script tags).

Usage

1. Open Chrome Devtools
2. Run the "create clean iframe" code
3. Switch to the "foo" console js context
4. Run the "find non-native functions" code
5. It will output any matches it finds

Next Steps

The usability could be improved drastically:

• Bookmarklet
• No need for chrome dev tools
• Output a nice reporting format
• Remove duplicates

Code quality: The code was just smashed together until it worked, it could use a fair amount of clean up and refactoring.

02_clean_iframe.js

var iframe = document.createElement("iframe");
iframe.id = "foo";
iframe.name = "foo";
document.body.appendChild(iframe);

03_find_overriden_functions.js

(function(){

  var getAllMethods = function(object) {
      return Object.getOwnPropertyNames(object).filter(function(property) {
          var isFunc = false;
          try {
            isFunc = typeof object[property] == 'function'
          } catch(e){
            isFunc = false;
          }
          return isFunc;
      });
  }

  var allObjects = Object.getOwnPropertyNames(window);
  var methods = [];

  for(var i = 0; i < allObjects.length; i++){
    var objStr = allObjects[i];
    try {
      var obj = eval(objStr);
    } catch(e){
      continue;
    }
    if(obj && objStr !== "parent" && objStr !== "top"){
      var objMethods = getAllMethods(obj);
      for(var j = 0; j < objMethods.length; j++){
        methods.push({objStr: objStr, obj: obj, method: objMethods[j]});
      }
    }
  }

  for(var i = 0; i < allObjects.length; i++){
    var objStr = allObjects[i] + ".prototype";

    try {
      var obj = eval(objStr);
    } catch(e){
      continue;
    }
    if(obj && objStr !== "parent" && objStr !== "top"){
      var objMethods = getAllMethods(obj);
      for(var j = 0; j < objMethods.length; j++){
        methods.push({objStr: objStr, obj: obj, method: objMethods[j]});
      }
    }
  }

  for(var i = 0; i < methods.length; i++){
    var method = methods[i];

    var parentObj;
    if(method.objStr.indexOf(".prototype") > 0){
      try {
        parentObj = window.parent[method.objStr.split(".prototype")[0]].prototype;
      } catch(e){ debugger; }
      
    } else {
      parentObj = window.parent[method.objStr]; 
    }

    if(parentObj){
      var parentObjMethod = parentObj[method.method];
      if(parentObjMethod){
        var parentObjMethodStr = parentObjMethod.toString();
        if(parentObjMethodStr.indexOf("{ [native code] }") === -1){
          console.log(method.objStr + "." + method.method + " =", parentObjMethodStr);
        }
      }
    }
  }
})();