Disable system restore and reboot, that will remove anyinfected restore point/s in system volume information. Schedule a boot time-scan from within avast if that comes up clean, you can enable system restore.
Leave the file in the avast Chest, a protected area where it can do no harm. You should leave it there for a week or two to ensure no harmful effects of having moved it. If there are no harmful effects, then scan it again if that scan also confirms it as infected you can delete it from within the chest.
A google.com search for Win32:Rameh returns lots of hits and would indicate it to be trojan downloader.