FSB operatives gave programmer Kirill Parubets an offer he couldn’t simply refuse: betray your friend, or face imprisonment yourself—possibly for life.

Not only did Parubets manage to escape this hopeless situation, but he also uncovered a program the FSB was using to spy on him—and likely others, including activists, their own employees, and agents: the Monocle spyware.

We explain in detail how he managed to break free, how Monocle works, and what you can do to avoid ending up in a similar situation.