Generating an exception list by a service provider for use in behavior monitoring programs for malware detection is described. A feedback server controlled by a malware prevention service provider receives client process reports from client devices owned by the service provider's customers and others using the provider's behavior monitoring software. The process reports contain data on processes that were evaluated (on the client device) as being processes that require a significant amount of CPU resources (i.e., above a certain threshold) to monitor and that have previously executed on the client device and were considered safe or non-harmful to the device. The feedback server receives the process reports and creates a statistics summary report, which is used by the service provider in evaluating whether to include the processes in the provider's official exception list which is distributed to its customers for use in their behavior monitoring programs. While creating the process reports on the client devices, the devices are able to temporarily address issues caused by processes taking up too much of the behavior monitor's CPU usage by including the process on exception list only for that client. The final decision as to whether the process will be on the final or official exception list is made by the service provider.