The need of wireless network is to enforce participating nodes to forward packets to other nodes to foster secure and reliable communication. Although there are presence of vulnerable nodes that can be associated with malicious nodes and can harm networks. The varieties of these malicious nodes are vulnerable to nodes which are either compromised or falsely guided by vulnerable nodes.Malicious nodes can easily tamper the participating nodes in the networks. In mobile ad hoc network these attacks shown their significance in the terms of network worms which can attack, alter or modify the root definitions of network across all administrative and participating domains.One of the sever attack is wormhole attack. In this attack tunneling of packets can be done with vulnerable nodes.This current book focuses on significant study of routing protocols used in MANET, as well as a detailed study and discussion on various network worms considering wormholes attacks in MANET,their detection and avoidance. However, the most significant contribution of this work is a quantitative study of performance based on different parameter before and after attack using different protocols using simulator.