Using Sentiment Analysis to Detect Insider Threats: It’s Not All About Time and Place

This is my first attempt to use AI tools like NotebookLM and ChatGPT to help dissect a white paper.

The paper I chose to analyze is: Sentiment classification for insider threat identification using metaheuristic optimized machine learning classifiers

If you are in a hurry here is the abstract of the paper:

This study examines the formidable and complex challenge of insider threats to organizational security, addressing risks such as ransomware incidents, data breaches, and extortion attempts. The research involves six experiments utilizing email, HTTP, and file content data. To combat insider threats, emerging Natural Language Processing techniques are employed in conjunction with powerful Machine Learning classifiers, specifically XGBoost and AdaBoost. The focus is on recognizing the sentiment and context of malicious actions, which are considered less prone to change compared to commonly tracked metrics like location and time of access. To enhance detection, a term frequency-inverse document frequency-based approach is introduced, providing a more robust, adaptable, and maintainable method. Moreover, the study acknowledges the significant impact of hyperparameter selection on classifier performance and employs various contemporary optimizers, including a modified version of the red fox optimization algorithm. The proposed approach undergoes testing in three simulated scenarios using a public dataset, showcasing commendable outcomes.

If you’d prefer I also had NotebookLM create a podcast of the paper.

A Quick Summary:

This study tackles the issue of insider threats—malicious acts by individuals within an organization—by analyzing data from emails, HTTP requests, and files to detect security breaches, like ransomware, data theft, and extortion.

Using advanced Natural Language Processing (NLP) for sentiment analysis and a Term Frequency-Inverse Document Frequency (TF-IDF) approach, the study encodes data to train XGBoost and AdaBoost classifiers. Improved detection accuracy is achieved by optimizing these models with a modified Red Fox Optimization algorithm, which balances exploration and exploitation in hyperparameter tuning.

Why Sentiment Analysis?

Sentiment analysis, in simple terms, is figuring out if the tone or feeling behind something—like an email or a document—is positive, negative, or neutral. Here, the researchers use sentiment analysis to examine how people interact with their systems. Are they feeling frustrated, sneaky, or maybe a little rebellious? The idea is that unusual emotional cues can serve as warning flags for potential insider threats.

The Tools of the Trade: NLP and TF-IDF

The researchers use NLP, the branch of artificial intelligence (AI) that deals with how machines understand language. They apply a fancy technique called Term Frequency-Inverse Document Frequency (TF-IDF), which essentially highlights words that appear often in one document but rarely in others. Imagine you’re a chef who specializes in spices; TF-IDF would help you spot rare spices in a dish rather than the common salt and pepper! In this case, it’s those unique, context-heavy words that may point toward a risky insider behavior.

The Real MVPs: XGBoost and AdaBoost

Now let’s meet the MVPs—XGBoost and AdaBoost. These are the machine learning algorithms that take our processed data and try to separate the innocents from the baddies.

  1. XGBoost: This is like a team of decision trees working together. The first tree tries, fails a bit, and learns from its mistakes, passing that learning onto the next tree in line. The result? A robust, mistake-correcting powerhouse of a model.
  2. AdaBoost: This one also combines multiple decision trees but with a twist. AdaBoost puts more weight on data points it previously messed up on, like a stubborn student determined to ace their weaknesses. It’s like having a detective team where each agent focuses more on unsolved cases than easy wins.

Hyperparameter Tuning: Meet the Red Fox Optimization (RFO) Algorithm

To really amp up these algorithms, the study introduces a modified Red Fox Optimization (RFO) algorithm. Named for the cunning red fox, RFO is inspired by how foxes hunt—combining a balance of exploration (looking for food) and exploitation (catching it). Hyperparameters are like dials on a soundboard; tuning them correctly makes all the difference. RFO fine-tunes XGBoost and AdaBoost to pick up the subtlest hints of insider malice.

And it’s not alone in the wild. RFO goes head-to-head with other nature-inspired algorithms: Genetic Algorithm (GA) (based on evolution), Particle Swarm Optimization (PSO) (mimicking bird flock behavior), and Artificial Bee Colony (ABC) (foraging bees). However, the modified RFO comes out on top, showing that the fox’s way of hunting is ideal for spotting insider threats.

Understanding the Inner Workings: SHAP (Shapley Additive Explanations)

Once our machine learning models have done their job, we still need to understand how they made their decisions. This is where SHAP (Shapley Additive Explanations) steps in. SHAP is like a window into the mind of the model, showing which words or behaviors it considers most suspicious. For instance, terms like “resume” and “job benefits” might seem innocent, but in certain contexts, they could hint at an insider preparing to jump ship—or worse, steal company secrets before leaving!

Metrics for Success

Finally, no study is complete without some scorecards. The study uses metrics like error rates (how often they’re wrong), Cohen’s Kappa (agreement between predicted and actual labels), precision (how many flagged threats are truly threats), sensitivity (catching as many threats as possible), and F1-score (the balance between precision and recall). This mix of metrics ensures the system isn’t just accurate but fair and balanced too.

Why This Matters

Detecting insider threats is a game of nuance. By understanding sentiment and context, this approach paints a fuller picture than just tracking times and places. It’s like spotting a plot twist in a novel by reading between the lines. And as it turns out, with a touch of machine learning and a dash of red-fox-inspired strategy, insider threat detection just got a lot more clever.