Favicorn is a command-line OSINT tool that searches for websites by their favicon hashes. It accepts input via favicon URL, file, or domain, computes multiple cryptographic and perceptual hashes (MMH3, MD5, SHA256, etc.), and generates search URLs for 11 security/search platforms (Shodan, ZoomEye, Censys, etc.). Optionally, it fetches and displays preview results from Shodan, ZoomEye, and Netlas using API keys. The architecture features a modular design: the Favicon class handles hash computation and platform-specific URL generation, while specialized Fetcher classes (Shodan, ZoomEye, Netlas) encapsulate API interactions, caching, and response parsing. The CLI orchestrates workflow, parallel execution, and output formatting. Key dependencies include requests, mmh3, dnspython, and platform-specific SDKs.