This work introduces NETA, a novel framework for the simulation of communication networks attacks. It is built on top of the INET framework and the OMNET++ simulator, using the generally accepted implementations of many different protocols, as well as models for mobility, battery consumption, channel errors, etc. NETA is intended to become an useful framework for researchers focused on the network security field. Its flexible design is appropriate for the implementation and evaluation of many types of attacks, doing it accurate for the benchmarking of current defense solutions under same testing conditions or for the development of new defense techniques. As a proof of concept, three different attacks have been implemented in NETA. The capabilities of NETA are exhibited by evaluating the performance of the three implemented attacks under different MANET deployments.