QuimaRAT is a Java-based remote access trojan (RAT) advertised under a malware-as-a-service (MaaS) model, capable of targeting Windows, Linux, and macOS. It features a modular architecture with encrypted plugins, supports multiple output formats, and includes tools like Quima Builder, Quima Loader, and Quima Dropper. It evades sandboxes, establishes persistence via OS-specific methods, and communicates over TCP, WebSocket, TLS, or HTTPS.