Add warning to FileDropper for deleting CWD

Author: wvu

lib/msf/core/exploit/file_dropper.rb

@@ -201,6 +201,10 @@ def file_dropper_delete_file(session, file)
   # @param [String] dir The directory to delete
   # @return [Boolean] True if the delete command has been executed in the remote machine, otherwise false.
   def file_dropper_delete_dir(session, dir)
+    if file_dropper_check_cwd?(dir)
+      print_warning("Attempting to delete working directory #{dir}")
+    end
+
     win_dir = file_dropper_win_path(dir)
 
     if session.type == 'meterpreter'
@@ -250,6 +254,26 @@ def file_dropper_deleted?(session, path, exists_before)
     end
   end
 
+  # Check if the path being removed is the same as the working directory
+  #
+  # @param [String] path The path to check
+  # @return [Boolean] true if the path is the same, otherwise false
+  def file_dropper_check_cwd?(path)
+    if session.type == 'meterpreter'
+      return true if path == session.fs.dir.pwd
+    else
+      pwd = if session.platform == 'windows'
+        session.shell_command_token('echo %cd%').strip
+      else
+        session.shell_command_token('pwd').strip
+      end
+
+      return true if path == pwd
+    end
+
+    false
+  end
+
   # Converts a path to use the windows separator '\'
   #
   # @param [String] path The path to convert