Have you visited any unusual sites or sites than you have never been before?
Have you downloaded anything recently that did not come from an official site?
Now im not much of a tech, but this trojan/virus seems to activate when you open up certain programs. i dont think the softnyx program itself is the problem, but the virus just chose to hide within its files. It has probably spreaded in your comp.
..not to scare ya ..
Anyways, What I would do .. or what most people would do..(if you havent done so already)
SPYBOT/AVG/AVAST/HOUSECALL/ADWARE your comp .
do whatever to remove it. If its one of those hard ones, I'd save all the files that I need (videos,homework projects,family pictures, documents) in a USB drive or so. Then system restore your computer. Wipe everything off as if it was brand new.
Then redownload whatever and be more cautious on what sites you go to....
I end up system restoring my comp every 3-5 months anyways. Just to be sure .
The reason as to why it does not get detected, is because the program install itself onto your computer as a legitimate security software when it is in fact not.
I got hit with a similar virus as well, I just reformatted since reinstalling windows 7 only took 3 minutes, and reinstalling my app takes a few hours. I rather no trust system restore when a virus or trojan is involve. if an app messes up duringing installation or uninstallation, then I will use system restore.
Back then, I use to be against windows' UAC, but these days I leave it on because I want to know everything that is happening on my pc. It's abit more work, but the results speaks for itself.