Subdomain 1.1: Explain core AI principles and terminology
1.Six months after deploying a highly accurate AI-based phishing detection model, the SOC manager notices a significant increase in false negatives. The attackers have started using new obfuscation techniques that were not present in the original training data. What AI concept explains this degradation in performance?
- A.Model drift
- B.Overfitting
- C.Underfitting
- D.Tokenization
Show answer & explanation
Correct answer: A — Model drift
- A. Model drift (specifically concept or data drift) refers to the degradation of a model's predictive power over time as the statistical properties of the data change. In cybersecurity, this typically occurs when adversaries evolve their tactics—such as using new obfuscation techniques—to bypass existing detection patterns that were established during the model's initial training phase.
- B. Overfitting occurs when a model learns the training data, including its noise and outliers, too closely, which prevents it from generalizing well to new, unseen data. While overfitting causes poor performance, it usually results in poor results immediately upon deployment; it does not explain why a previously 'highly accurate' model would degrade months later.
- C. Underfitting happens when a model is too simplistic to capture the underlying patterns in the data, leading to poor performance on both training and real-world data. This does not apply here because the model was initially highly accurate, indicating it had successfully captured the relevant patterns at the time of deployment.
- D. Tokenization is a fundamental Natural Language Processing (NLP) preprocessing step where text is broken down into smaller units, such as words, phrases, or symbols. While it is used in building phishing detection models, it is a data preparation technique and is not a cause for performance degradation over time.