I have come across this nasty virus (SVC:swcustcfg) i am unable to apply it to the chest or delete it, please help as my computer is so slow and keeps wanting to shut down.
:o 
Hi that file is related to ZeroCD Sierra Wireless and I have come across this before, it is a false positive.
What it is, is that the registry data give a null value and that raises a red flag to Avast
If it is coming up on the rootkit scan then set it to ignore