Detekt is a free tool that can detect sophisticated monitoring programs such as, FinFisher a.k.a FinSpy and Hacking Team RCS. This tool doesn't guarantee detection of all spyware, so don't consider this as an alternative to the anti-virus/anti-spyware software. It was mainly developed to protect the human rights defenders and journalists from the surveillance, but now it is much popular and used by almost every internet user.
ABOUT FINSPY & HACKING TEAM RCS
FinSpy and Hacking Team RCS are the most sophisticated monitoring programs designed to spy on individuals and organizations. These two Spywares are capable of many things including monitoring of encrypted communications.