Hi, I can help you develop the Anti-Ransomware Program; I have written similar software to detect and remove Rootkits.
The program would use a File System Filter Driver to intercept all requests that read and modify files performed by unauthorized/suspicious processes. The backup would be 100% safe by using this same driver so that only the Anti-Ransomware program can access it.
For a modern UI, I can create it using either QML(C++) or WPF(C#). whichever you prefer.