Described is a system for detecting adversarial activities based on detection of activity patterns in a multiplex network. The system detects one or more subnetworks that are matches to a template network of template nodes. The subnetworks are detected by filtering multiplex network nodes according to a filtering criteria that utilizes monotone function properties in the multiplex network. Nodes that do not meet the filtering criteria are eliminated, resulting in a list of candidate nodes in the multiplex network. The one or more subnetworks are formed from the list of candidate nodes. An activity pattern corresponding to a pattern of adversarial activity is identified in the one or more subnetworks. Based on the identified activity pattern, an alert of adversarial activity is generated and transmitted.