dump dynamically created files to local

TODO add documentation

dump_dynamically_created_files.py

@@ -0,0 +1,119 @@
+import os
+import sys
+import frida
+
+APP_NAME = 'com.package.name'
+
+
+def on_message(message, _ignored_data):
+    if message['type'] == 'send':
+        if type(message['payload']) == dict:
+            os.makedirs(os.path.dirname('./dump/{}/'.format(APP_NAME)), exist_ok=True)  # create sub folder if not exist
+            with open('./dump/{}/{}'.format(APP_NAME, message['payload']['file']), 'w') as d:
+                for element in message['payload']['content']:
+                        d.write(chr(element % 256))
+                d.close()
+            print('[*] Successfully dumped to {0}'.format(message['payload']['file']))
+        else:
+            print('[*] {0}'.format(message['payload'].encode('utf-8')))
+    else:
+        print(message)
+
+
+js_code = """
+    Java.perform(function() {
+        var openedfile = "";
+        var data = {
+            "file": "",
+            "content": []
+        };
+        var isOpen = false;
+        var index = 0;
+    
+        var fos = Java.use('java.io.FileOutputStream');
+    
+        var fos_construct_2 = fos.$init.overload('java.lang.String');
+        var fos_construct_3 = fos.$init.overload('java.io.File');
+        var fos_construct_4 = fos.$init.overload('java.lang.String', 'boolean');
+        var fos_construct_5 = fos.$init.overload('java.io.File', 'boolean');
+    
+        var fos_write_1 = fos.write.overload('[B', 'int', 'int');
+    
+        var fos_close = fos.close;
+    
+        function dump(data) {
+            send("Got " + data["content"].length + " bytes!");
+            var tmp_name = openedfile.split("/");
+            tmp_name = tmp_name[tmp_name.length - 1];
+            data["file"] = tmp_name;
+            send(data);
+            data["content"] = [];
+            index = 0;
+        }
+    
+        fos_construct_2.implementation = function(file) {
+            var filename = file;
+            if (openedfile != filename) {
+                openedfile = filename;
+                send("File opened for write " + filename);
+                isOpen = true;
+            }
+            return fos_construct_2.call(this, file);
+        }
+    
+        fos_construct_3.implementation = function(file) {
+            var filename = file.getAbsolutePath();
+            if (openedfile != filename) {
+                openedfile = filename;
+                send("File opened for write " + filename);
+                isOpen = true;
+            }
+            return fos_construct_3.call(this, file);
+        }
+    
+        fos_construct_4.implementation = function(file, true_false) {
+            var filename = file;
+            if (openedfile != filename) {
+                openedfile = filename;
+                send("File opened for write " + filename);
+                isOpen = true;
+            }
+            return fos_construct_4.call(this, file, true_false);
+        }
+    
+        fos_construct_5.implementation = function(file, true_false) {
+            var filename = file.getAbsolutePath();
+            if (openedfile != filename) {
+                openedfile = filename;
+                send("File opened for write " + filename);
+                isOpen = true;
+            }
+            return fos_construct_5.call(this, file, true_false);
+        }
+    
+        fos_write_1.implementation = function(arr, offset, length) {
+            var i = 0;
+            for (i = offset; i < length; i = i + 1) {
+                data["content"][index] = arr[i];
+                index = index + 1;
+            }
+            return fos_write_1.call(this, arr, offset, length);
+        }
+    
+        fos_close.implementation = function() {
+            dump(data);
+            return fos_close.call(this);
+        }
+    
+    });
+"""
+
+device = frida.get_usb_device()
+pid = device.spawn([APP_NAME])
+session = device.attach(pid)
+script = session.create_script(js_code)
+print("[*] Intercepting [{}]".format(pid))
+script.on('message', on_message)
+script.load()
+device.resume(APP_NAME)
+sys.stdin.read()