The following is an answer given to sumone who asked what a virus does in the Chest :
There is no rush to delete anything from the chest, a protected area where it can do no harm. Anything that you send to the chest you should leave there for a few weeks. If after that time you have suffered no adverse effects from moving these to the chest, scan them again (inside the chest) and if they are still detected as viruses, delete them.
My Question is: Is there any harm if i don’t delete the infected file from the Chest at all? In other words, what if I send the infected files to the Chest and totally forget about them? Is there any harm?
No harm whatsoever. Unless you or another user should restore a virus from the chest, maliciously or ignorantly or absent-mindedly. (All a bit unlikely, probably.)
It is just considered good housekeeping, to a degree, and the nature of the housekeeping depends on you.
I still have old viruses in my chest. Must delete them in a few years before I loose my marbles.
If you ever uninstall the program, the viruses will be deleted harmlessly, along with the chest.
The only disadvantage is the space that they take up (minimal in most cases), personally If after a reasonable time having scanned them again and found them to still be infected there is little point in keeping them, unless you have another purpose that you haven’t mentioned.
The purpose of the delay is to ensure that the detection was good, false positive detections can happen and by keeping it in the chest for some time, any good file that was missing would likely show in an adverse effect (a program might not run, etc.).
This also gives time to see if someone else has noticed the same detection but found an adverse effect and reported it. Then avast would reanalysis it and possibly correct the detection, so when you scan it within the chest you may find it is no longer detected and it can be restored. The purpose of the delay is one of caution, never be in a rush to delete.