andt.sys .. torjan horse

[gazzazh]

 i have recently discovered the Trojan horse known as (andt.sys) in my system32 folder (windows vista 32bit)
when avast scans , it finds the virus , but when i try to delete or move to chest .. it says access denied.. when i try to schdual a boot scan it says access denied.
if i remove the file manually .. it comes back again ... please help  :'(

[Lisandro]

Download ComboFix from Here or Here to your Desktop.

Double click combofix.exe and follow the prompts.

When finished, it shall produce a log for you. Post that log and a HiJackthis log in your next reply

Note: Do not mouseclick combofix's window while its running. That may cause it to stall.