Ad hoc mobile networks (MANET) vary greatly depending on their application area and environment in which they work. We have presented a brief review of the state of the art security scenario for MANETs and also pinpointed some of the loopholes of the existing Intrusion Detection Systems (IDS) before we proposed a new collaborative algorithm called IDSX. The proposed IDSX offers an extended architecture and is compatible with heterogeneous IDS already deployed in the participating nodes. While maintaining a high level of intrusion detection, the proposed solution virtually eliminates the problem of phantom intrusion detection to a great extent by aggregating the locally generated alerts to keep or discard a suspected intruder in a two step process.