This article outlines a method to create a Rust binary that behaves harmlessly under normal circumstances but runs a hidden program on a specific target host. It discusses the encryption of the hidden program and how to derive a decryption key from unique host data, ensuring the hidden code remains concealed. The approach is relevant for targeted malware and software licensing.

SimpleCrypt is a Rust-based command-line tool designed for secure file and directory encryption using AES-256-CBC and PBKDF2 key derivation. It offers features like progress feedback, secure memory practices, and comprehensive error handling across multiple platforms, while emphasizing strong password usage and secure password management. Users are encouraged to follow best practices for encryption and data handling to ensure security.