This is just to let you know I had to remove Avast Pro because apparently it does not detect all threats.
No security program have 100% detection or zero false positives. If they did there would not be a malware problem
Oddly enough, a competing product DID detect and has removed said virus.... or at least appears to have done so.. I will know in a few days if IE does not open itself again all on its own.
What program and what did it detect ? From description it seems you had a HTML fake alert