Toward Classifying Unknown Application Traffic
DYnamic and Novel Advances in Machine Learning and Intelligent Cyber Security (DYNAMICS) Workshop (DYNAMICS) 2018.
Determining the particular application associated with a given flow of internet traffic is an important security measure in computer networks. This practice is significant as it can aid in detecting intru- sions and other anomalies, as well as identifying misuse associated with prohibited applications. Many efforts have been expended to create models for classifying internet traffic using machine learning techniques. While research so far has proven useful, studies have focused on machine learning techniques for detecting well-known and profiled applications. Some have focused only on particular transport layer traffic (e.g., TCP traffic only). In contrast, unknown traffic is much more difficult to classify and can appear as previously unseen applications or established applications exhibiting abnormal behavior. This work presents methods to address these gaps in other research. The methods utilize k-Nearest Neighbor machine learning approaches to model known application data with the Kolmogorov-Smirnov statistic as the distance function to computer nearest neighbors. The models identify incoming data which likely does not belong to the model, thus identifying unknown applications. This study shows the potential of our approach by presenting results which show successful implementation for a controlled environment, such as an organization with a fixed number of approved applications. In this setting, our approach can distinguish unknown data from known data with accuracy up to 93 percent compared to an accuracy of 57 percent for a strawman k-Nearest Neighbors approach with Euclidean distance. In addition, there are no restrictions on particular protocols. Operational considerations are also discussed, with emphasis on future work that can be performed such as exploring processing of incoming data in real-time and updating the model in an automated way.