Avast isn’t detecting them and it certainly isn’t deleting them, the problem as experienced relating to BSOD on boot is showing an avast file as responsible for the BSOD, but that is incorrect as that was the last file loaded before it.

This relates to a bad windows KB update (as essexboy and Bob mentioned) which was causing problems (BSOD) on some systems. This resulted in the KB update being withdrawn from windows update.

If you are saying it is detecting them (based on your reading of the forums), we need the file name, location and malware name, which I doubt you will find as it isn’t detecting them.