Moving Targets: Addressing Concept Drift in Supervised Models for Hacker Communication Detection

In this paper, we are investigating the presence of concept drift in machine learning models for detection of hacker communications posted in social media and hacker forums. The supervised models in this experiment are analysed in terms of performance over time by different sources of data (Surface web and Deep web). Additionally, to simulate real-world situations, these models are evaluated using time-stamped messages from our datasets, posted over time on social media platforms. We have found that models applied to hacker forums (deep web) presents an accuracy deterioration in less than a 1-year period, whereas models applied to Twitter (surface web) have not shown a decrease in accuracy for the same period of time. The problem is alleviated by retraining the model with new instances (and applying weights) in order to reduce the effects of concept drift. While our results indicated that performance degradation due to concept drift is avoided by 50% relabelling, which is challenging in real-world scenarios, our work paves the way to more targeted concept drift solutions to reduce the re-training tasks.