A computer system is provided. The computer system includes a memory and at least one processor coupled to the memory and configured to detect triggering of one or more threat detectors. The at least one processor is further configured to activate a subset of nodes from a plurality of nodes in a Bayesian network in response to the detection, the activated subset of nodes associated with the triggered threat detectors. The at least one processor is further configured to calculate a probability of malicious action using the Bayesian network to combine probabilities associated with the activated subset of nodes. The at least one processor is further configured to determine that the probability exceeds a threshold value. The at least one processor is further configured to perform a security action in response to the determination.