It depends on how you use your configuration and how the virus
works. EWF protects the drive on a sector level. So any
files/registry keys the virus tries to write will go to the overlay.
So if your device reboots frequently without commits, then
the risk of a virus impacting you is much less than if you run
with the same overlay forever or God forbid commit an infected
overlay.
Keep in mind that a virus can still do bad things even if it isn't
committed. It might take up ports, or corrupt your overlay, or
send email out from the machine, etc etc.
-Bill
