1. A method for detecting network anomalies, the method comprising: receiving, by a hardware processor, a communication protocol message having an argument string that is transmitted from a first processor to a second processor across a computer network; applying a probabilistic model to the received communication protocol message to determine whether the communication protocol message is anomalous based on determining that at least one n-gram in the communication protocol message is anomalous, wherein the probabilistic model uses at least one Markov chain specified by one or more parameters to determine a probability that the argument string is anomalous based on n-grams in the argument string, and wherein the probabilistic model was trained based on content and structure of an argument string included in each of a plurality of communication protocol messages included in a training dataset; and performing a predetermined action in response to determining that the communication protocol message is anomalous.