added on_new_session handler to warn users about cleanup

modules/exploits/windows/browser/keyhelp_launchtripane_exec.rb

@@ -85,6 +85,10 @@ class Metasploit3 < Msf::Exploit::Remote
 			], self.class)
 	end
 
+	# The following handles deleting the copied vbs payload and mof file
+	def on_new_session(client)
+		print_status("The exe payload (C:\\windows\\system32\\msfmsf.exe) and mof file (C:\\windows\\system32\\wbem\\mof\\good\\msfmsf.mof) must be removed manually.")
+	end
 
 	def auto_target(cli, request)
 		agent = request.headers['User-Agent']