IRCFLOOD Malware

every time I scan my computer with Secuser antivirus online it founds me a ircflood malware that is not detected by Avast. Secuser deletes it, but this malware comes back after every shutdown of my computer … It seems to come back in fact when I open Mirc. I have uninstalled Mirc and reinstalled it again. But it’s always there !
Any idea how to get this “thing” out of my pc ??

  1. update windows
  2. scan with spybot S&D or Ad-Aware or better BOTH
  3. perform manual program and database update on avast ( the program is NOT automatically updated by default)

Windows is updated
Avast also …
I will try spybot.

Thanks