If ransomeware had a timer i think you are done right now
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
If your system is still alive check the massage box and Compare it with famous ransomwares massage boxes.
Most people using Free opensource ransomwares this days and most of them have a backdoor created by the coder of project.(because they are for educational purpose)
Check "hidden tear" on the internet and maybe you could Learn more about it.