Over a past two decades, Telecom industry is growing and mode of communication is changing and advanced day by day for catering individual and corporate needs. With the growth and advancement of technologies, telecom frauds are the major concern for research area and delivering the cent percent revenue in the system. Telecommunications fraud is a problem that affects operators all around the globe and one of the most known frauds is illegal to bypass fraud which is used in International voice traffic, in order to avoid carrier charges and this causes opportunity loss of international interconnect usage charge (IUC) to operators and this is major concern for research scope and impacting the revenue at operator level. As a result, cellular operators around the globe lose billions annually. Moreover, SIM box compromises the cellular network infrastructure by overloading local base stations serving these devices. This paper analyses the fraudulent termination of international traffic so suggest statistical, conventional, modern approach for detection of sim box and processes hundreds of millions of anonymized voice call detail records (CDRs). Their outputs of these models are optimally fused to increase the detection rate of sim box. The operator’s fraud department confirmed that the algorithm succeeds in detecting new fraudulent SIM box.