The rapid development of Internet of Things (IoT) technology and the expansion of various application domain services have led to an increase in the importance of service integrity, system security, and device control in IoT environments. Despite frequent security breach incidents in cloud server-oriented IoT services and increasing security threats to various IoT devices in smart cities and smart homes, blockchain-IoT studies that aim to fuse IoT with blockchain are gaining recognition. Blockchain technology is being extensively applied in daily life through smart contracts using decentralized applications (DApps). A smart contract is a digitally written contract that records contract terms in the blockchain and automatically executes contracts when the prescribed terms are met, which can enhance reliability, stability, and security in IoT environments. However, because the generated blocks cannot be modified or deleted, security flaws can occur if the contract is not written perfectly, resulting in huge monetary losses and impeding the ecological stability of the contract layer of a blockchain. In this paper, we present an analyzer that can diagnose the security weaknesses in the code constituting the contract in advance when developing DApp-based software