USENIX Security2026

SoK: PHILTER: Uncovering Security and Functional Gaps in AI-based Phishing Website Detection Literature via an LLM-based Reasoning Framework

Mahbub Alam, Muhammad Lutfor Rahman, Sonjoy Kumar Paul, Amy W. Hays, Aftab Hussain, Md Imanul Huq, Nitesh Saxena

Abstract

Phishing websites remain a dominant enabler of cybercrime. In response, many academic AI-based phishing website detection methods have been developed, often inspiring the design of real-world systems. Although most studies report high accuracy, it remains unclear whether they meet real-world requirements such as resilience to evolving phishing tactics, robustness on diverse benign pages, interpretability, and privacy. We present PHILTER (PHishing detection literature Inspection via LLMs and Targeted Expert Review), a scalable framework for qualitatively assessing phishing website detection studies across four functionality and three security metrics. PHILTER leverages LLMs to extract evidence and draft rationales, which experts then validate and use to produce the final assessment. Applying it to 55 academic approaches reveals systemic gaps. No study fulfills all functionality and security requirements. None show evidence of effectively addressing diverse phishing tactics. Most approaches struggle to preserve privacy and adapt to evolving attacker strategies, and many risk elevated false alarms in practice due to limited testing on diverse benign pages. We also introduce a taxonomy of detection strategies (feature-based, similarity-based, identity-based, and hybrid) that highlights design trade-offs and helps explain these shortcomings. Our study reveals that accuracy-driven evaluation overlooks blind spots that undermine practical effectiveness and exposes a key open challenge: achieving high accuracy while fulfilling all functionality and security requirements. We provide actionable recommendations to guide the design of future defenses that pursue this simultaneous goal against evolving and adaptive phishing campaigns.