Abstract: Wireless ad-hoc sensor networks and routing data in them is a significant research area. The objective of this paper is to examine resource depletion attacks at the routing protocol layer, which attempts to permanently disable network nodes by quickly draining their battery power. This type of attack is called as vampire attack. Vampire attacks are very difficult to detect because they attack the node only by sending protocol-compliant messages. These attacks are not specific to any protocol, but rather rely on the properties of many popular classes of routing protocols. In the worst case, a single Vampire can increase network-wide energy usage by a factor of O (N), where N is the number of network nodes. Methods to detect and secure data packets from vampires during the packet forwarding phase is discussed. PLGP with attestations (PLGP-a) is used for identifying malicious attack. M-DSDV routing protocol is used to detect and eliminate the resource depletion attack from the network.