Let's make an open-source virus while we’re at it? Your target audience is very small, you're not going to get much help, and you'll be exposing any undiscovered vulnerability to state entities that have the resources to exploit them at the cost of the operator's freedom. Open source only works if you have a healthy number of eyes working on it otherwise you're better off with security through obscurity. Think of how many people work on the linux kernal and how bugs are still found all the time
Asking for a friend interested in civil liberties and civil disobedience.