If you're looking for a free and open-source tool to detect and block malicious websites and assets in the Web3 ecosystem, Web3 Antivirus is a great option. This browser extension offers a range of security features, including transaction simulation, advanced risk assessment, proactive phishing protection and a blocklist of more than 934,000 known malicious sites. It currently supports Ethereum transactions, but will expand to other chains, and it can be used with MetaMask. You can install it without connecting a wallet, so it's a good, secure and trustworthy option for Web3 protection.
For a more general-purpose tool that extends beyond Web3 security, Beagle Security offers AI-powered penetration testing for web applications, APIs and GraphQL endpoints. It comes with features like DAST, compliance reporting and vendor onboarding that can help you identify and remediate vulnerabilities in your web apps. It's highly customizable and integrates with other security tools, so it's a good option for teams that focus on app security.