Leave them in the chest (they can't do any harm there) for a week or two so as to ensure that there are no harmful effects from them having been moved there (incorrect detection, etc.). This gives you time to investigate if at all possible (google search, ask here, etc.) to confirm.
You can then delete, restore or move them from within the chest, whichever is appropriate. Right click the avast icon and select Program Settings... then select Chest.