MANET is a temporary network for a specified work and with the enormous growth MANETs it is becoming important and simultaneously challenging to protect this network from attacks and other threats. Packet drop attack or gray hole attack is the easiest way to make a denial of service in these dynamic networks. In this attack the malicious node reflects itself as the shortest path and receives all the packets and drops the selected packets in order to give the user the service that that is not correct. It is a specific kind of attack and protects the network and user from detecting this malicious activity. In this article I have proposed an efficient for step technique that confirms that this attack can be detected and defended with least efforts and resource consumption.