PROXiFY: A Bytecode Analysis Tool for Detecting and Classifying Proxy Contracts in Ethereum Smart Contracts

As Ethereum smart contracts grow in complexity, upgrades are necessary but challenging due to their immutable nature. Proxy contracts enable upgrades without changing contract state, but current detection approaches often rely on source code or transaction history and fail to detect inactive proxies. Detecting these proxies is critical because dormant upgrade paths can be reactivated, introducing risks and potential attacks. We introduce PROXiFY, a lightweight bytecode-based tool that detects and classifies proxy contracts, including inactive ones, without requiring Ethereum nodes, source code, or customized EVMs. PROXiFY achieves a precision of 98.6% and recall of 97.1% on a high-confidence benchmark dataset. A demonstration of PROXiFY can be viewed at https://youtu.be/FuYs22_vosk.