Sadly I have been hit several times in the same file
location.
  It has never vanished in one swipe, avg will say to run
it to remove it but when you run it , it doesn't find it.
Weird isn't it...it reports for you to run it because it has
found it and then can't find it.  It used to frustrate me.
  But eventually it will get removed.  You need to go to
safe mode, keep hitting the F8 as your files start loading
as you are coming up from a reboot.
Run your AD-aware, I suppose you could run Nortons
too and do a deep search each time.
  Then continue about your business, reboot and to get
out of safe mode.
You will probably get some more errors so run avg scans
every day and after every reboot.  It will disappear within
a couple days or earlier.
   Don't get bummed out...