raman
4
Like kubecj said, the file is the Windows swapfile and will recreated after each restart. It is possible that Windows swap out the Memory that the Avast scanner or Guard is/was using and so the signatures could be swapped out too. ANd than avast get fooled by its own signature. To avoid this, do not start or load AVAST while using Windows! But i do not think that you want that!
Just do no bootscan or delete the Swapfile on shutdown. There is an option in windows to do so, but it slows down the shutdown (more than a minute)