which file in avast! is used to scan the receiving files in MSN?

Avast Free Antivirus / Premium Security
1

I want to find out which file(.exe) in avast! folder is used in MSN for scanning virus when I receive files from my friend

2

Assuming that you installed avast! in the default folder, this is the path needed to scan downloads, C:\Program Files\Alwil Software\Avast4\ashQuick.exe