A method and system for the automatic determination of the behavioral profile of a program suspected of having worm-like characteristics includes analyzing data processing system resources required by the program and, if the required resources are not indicative of the program having worm-like characteristics, running the program in a controlled non-network environment while monitoring and logging accesses to system resources to determine the behavior of the program in the non-network environment. A logged record of the observed behavior is analyzed to determine if the behavior is indicative of the program having worm-like characteristics. The non-network environment may simulate the appearance of a network to the program, without emulating the operation of the network.