System, apparatus, computer program products and methods for preventing fraud attacks (e.g., on a virtual PBX service provider) are disclosed. In some implementations, a set of fraud evaluation processes are performed, an overall fraud evaluation score is incremented as each of the set of fraud evaluation processes are performed and a step result is obtained. A user request (e.g., account activation) can be denied or accepted based on the overall fraud evaluation score. In some implementations, the set of fraud evaluation processes can include one or more of: an internal fraud evaluation process, a process for checking multiple trial accounts associated with a common account parameter, a process for geolocation verification of multiple account parameters, a process for device type verification for a contact phone number, a process for credit card verification, and a process for placing a contact number verification call.