<![CDATA[Online gambling sites in Indonesia generated IDR 155.4 trillion in transactions in 2025 with 3.2 million active players, yet DNS filtering the dominant countermeasure blocks only 0.64% of observed gambling traffic. Network-layer approaches fail structurally: they cannot intercept content via VPN, DNS-over-HTTPS, or direct IP access, and they cannot detect the domain neutralization used by the majority of Indonesian gambling operators. This paper proposes GUPI (Gambling URL Pattern Interceptor), a Chrome Extension implementing a three-layer cascade detection architecture running entirely client-side under Manifest V3 without external server dependencies. Layer 1 applies weighted lexical scoring to URL features. Layer 2 applies DOM keyword pattern matching with conditional context suppression. Layer 3 applies CSS selector-based DOM structural heuristic scoring to detect gambling-characteristic page architectures when text-level signals are absent. GUPI was evaluated on 926 URLs (326 gambling, 600 benign) across three sequential configurations. The full system achieves 98.81% accuracy, 99.07% precision, 97.55% recall, 98.30% F1-score, and 0.50% false positive rate. ]]>
Copyrights © 2026
