If this is truly a virus, I like Eset Nod32 because of it's scoring. I'm not sure if the online scanners will find a virus using rootkit technology, but Eset (and many others) have free online scanners.
Other free online anti-virus scanners:
If you search for free online scanners and stick to the major name brands you will find a few. If you want, you can run two or three and if they don't find anything, either your in the clear or you have a deeper problem (rootkit).
There were some free rootkit detectors, one you may want to run is Microsoft RootkitRevealer.
Hopefully, the slowness is just a sign of slow hardware, or visual studio spinning up your app or running your app in debug mode. While that won't speed things up, but it's better than having a virus.