trojan horse Delf.HNS

my pc is infected by trojan horse Delf.HNS according to AVG anti-virus…i also tried to run Spyware Terminator, Super Anti-Spyware and Spybot Search & Destroy in my pc but they did not detect that, only AVG Anti-virus had that detection…my question is: is that really a virus threat? if it’s indeed a virus how can i remove and get rid of it? but if not, how can i avoid being annoyed by a dialog box of that virus threat according to AVG?