Evasion: scramble now stores random values in the config object, in order to be re-used later on in a consistent way.

extensions/evasion/config.yaml

@@ -20,5 +20,7 @@ beef:
             name: 'Evasion'
             authors: ["antisnatchor"]
             scramble_variables: true
-            to_scramble: ["beef", "Beef"]
+            scramble:
+              beef: "beef"
+              Beef: "Beef"
             chain: ["scramble","minify","base_64"]

extensions/evasion/evasion.rb

@@ -29,6 +29,10 @@ module BeEF
             @input = apply_chain(input, @@techniques)
           end
 
+          def inject_boostrapper(input)
+             # add stuff at the end, only once (when serving the initial init javascript)
+          end
+
           def apply_chain(input, techniques)
             @output = input
             techniques.each do |technique|

extensions/evasion/extension.rb

@@ -26,6 +26,7 @@ end
 end
 
 require 'extensions/evasion/evasion'
+require 'extensions/evasion/helper'
 require 'extensions/evasion/obfuscation/scramble'
 require 'extensions/evasion/obfuscation/minify'
 require 'extensions/evasion/obfuscation/base_64'

extensions/evasion/obfuscation/base_64.rb

@@ -19,18 +19,11 @@ module BeEF
       class Base_64
         include Singleton
 
-        def random_string(length=5)
-          chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ'
-          result = ''
-          length.times { result << chars[rand(chars.size)] }
-          result
-        end
-
         def execute(input, config)
           encoded = Base64.strict_encode64(input)
           # basically, use atob if supported otherwise a normal base64 JS implementation (ie.: IE :-)
           decode_function = 'var _0x33db=["\x61\x74\x6F\x62","\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4A\x4B\x4C\x4D\x4E\x4F\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5A\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6A\x6B\x6C\x6D\x6E\x6F\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7A\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x2B\x2F\x3D","","\x63\x68\x61\x72\x41\x74","\x69\x6E\x64\x65\x78\x4F\x66","\x66\x72\x6F\x6D\x43\x68\x61\x72\x43\x6F\x64\x65","\x6C\x65\x6E\x67\x74\x68","\x6A\x6F\x69\x6E"];function dec(_0x487fx2){if(window[_0x33db[0]]){return atob(_0x487fx2);} ;var _0x487fx3=_0x33db[1];var _0x487fx4,_0x487fx5,_0x487fx6,_0x487fx7,_0x487fx8,_0x487fx9,_0x487fxa,_0x487fxb,_0x487fxc=0,_0x487fxd=0,dec=_0x33db[2],_0x487fxe=[];if(!_0x487fx2){return _0x487fx2;} ;_0x487fx2+=_0x33db[2];do{_0x487fx7=_0x487fx3[_0x33db[4]](_0x487fx2[_0x33db[3]](_0x487fxc++));_0x487fx8=_0x487fx3[_0x33db[4]](_0x487fx2[_0x33db[3]](_0x487fxc++));_0x487fx9=_0x487fx3[_0x33db[4]](_0x487fx2[_0x33db[3]](_0x487fxc++));_0x487fxa=_0x487fx3[_0x33db[4]](_0x487fx2[_0x33db[3]](_0x487fxc++));_0x487fxb=_0x487fx7<<18|_0x487fx8<<12|_0x487fx9<<6|_0x487fxa;_0x487fx4=_0x487fxb>>16&0xff;_0x487fx5=_0x487fxb>>8&0xff;_0x487fx6=_0x487fxb&0xff;if(_0x487fx9==64){_0x487fxe[_0x487fxd++]=String[_0x33db[5]](_0x487fx4);} else {if(_0x487fxa==64){_0x487fxe[_0x487fxd++]=String[_0x33db[5]](_0x487fx4,_0x487fx5);} else {_0x487fxe[_0x487fxd++]=String[_0x33db[5]](_0x487fx4,_0x487fx5,_0x487fx6);} ;} ;} while(_0x487fxc<_0x487fx2[_0x33db[6]]);;dec=_0x487fxe[_0x33db[7]](_0x33db[2]);return dec;};'
-          var_name = random_string(3)
+          var_name = BeEF::Extension::Evasion::Helper::random_string(3)
           input = "var #{var_name}=\"#{encoded}\";#{decode_function}[].constructor.constructor(dec(#{var_name}))();"
           print_debug "[OBFUSCATION - BASE64] Javascript has been base64'ed'"
           input

extensions/evasion/obfuscation/scramble.rb

@@ -19,28 +19,24 @@ module BeEF
       class Scramble
         include Singleton
 
-        def random_string(length=5)
-          chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ'
-          result = ''
-          length.times { result << chars[rand(chars.size)] }
-          result
-        end
-
         def execute(input, config)
-          to_scramble = config.get('beef.extension.evasion.to_scramble')
-          to_scramble.each do |var|
-             mod_var = random_string
-             input = input.gsub!(var,random_string)
-             print_debug "[OBFUSCATION - SCRAMBLER] string [#{var}] scrambled -> [#{mod_var}]"
-
-             #todo: add scrambled vars to an Hash.
-             #todo: even better. Add them to the Configuration object, like "beef" => "cnjD3"
-             #@@to_scramble = config.get('beef.http.evasion.scramble_variables')
-             #@@scrambled = Hash.new
+          to_scramble = config.get('beef.extension.evasion.scramble')
+          to_scramble.each do |var, value|
+             key = config.get("beef.extension.evasion.scramble.#{var}")
+             if value == key
+               # Variables have not been scrambled yet
+               mod_var = BeEF::Extension::Evasion::Helper::random_string(3)
+               input = input.gsub!(var,mod_var)
+               config.set("beef.extension.evasion.scramble.#{var}",mod_var)
+               print_debug "[OBFUSCATION - SCRAMBLER] string [#{var}] scrambled -> [#{mod_var}]"
+             else
+               # Variables already scrambled, re-use the one already created to maintain consistency
+               input = input.gsub!(var,value)
+               print_debug "[OBFUSCATION - SCRAMBLER] string [#{var}] scrambled -> [#{value}]"
+             end
           end
            input
         end
-
       end
     end
   end