Ad-hoc network is a wireless structure composed of number of nodes,where each node can move independently without depending on any centralized access to maintain and control them. Such that each node can forward the data with the help of neighbour node. In that case them is behaviour act is termed as selfish,when the node,which does not want to forward the data to keep,safeguard it resources,this will degrade the network performance. One more issue in ad-hoc is hackers,who can easily hack the information because of its infrastructure less network; this can be done by identifying the malicious node. Thus the watchdog is one of mechanism to detect the selfish node by overhearing a packet during data transfer between the nodes. But one of the issues in watchdog mechanism is that it will render the incorrect results produced by false positives and negatives. To overcome this we introduce a local watchdog mechanism with improved step to decrease the detection time of selfish node by incorporating concepts such as detecting event,dissemination of events and update the event information to the neighbour node,so that the forwarding node will easily identify the selfish node and will not forward any packets to selfish node. To detect a malicious node we use the cryptography mechanism viz. MD5 algorithm to generate the signature. If the generated signature does not match with receiver signature then the malware is detected. By detecting selfish and malicious node in network the overall performance of the wireless network will be improved. © 2016,International Journal of Pharmacy and Technology. All rights reserved.