In addition to Shintaro's idea you might also try what I always recommend: the use of three free items (find links in our Freeware DB
First in normal boot mode, download TDSSKiller
. Then download, install, and allow to update Malwarebytes Anti-Malware (MBAM)
. Since you already have an active anti-virus make sure you use only the passive version of MBAM; make sure any time it offers to activate the 30-day free trial (on install and each use) that you do not select OK.
Then reboot your system into safe mode without networking (Reboot and, when it says "Starting Windows," Press F8; If you get a message asking continue in safe mode or perform a system restore, choose continue in safe mode). Now run TDSSKiller and after that run RKill and after that run a full MBAM virus scan. The first two will take maybe 5 minutes each but a full virus scan can take anywhere from 30 minutes to several hours depending on your hard drive size and number of files.
Booting in safe mode makes sure only minimal services/programs are started. TDSSKiller is designed specifically to look for rootkits. RKill is designed to stop the stealthing programs that hide/protect/regenerate some nasty viruses. Running these first will help ensure MBAM has the absolute best chance of cleaning up infected files.