This has also occurred for me today. Once was 15GB of RAM the second time was 8GB of RAM used. Once was while using Firefox another time I was using my CD burning software.
It creates a thread every minute, does a bunch of file read (VBoxC.dll) and some file creation operations to disk.sdi, layout.dat, registry files in the NG directory and then closes the thread. Only to repeat all of this again a minute later as RAM utilization climbs each time.
(link is a screenshot of TaskManager showing memory usage)
UPDATE
After doing some research on Avast NG and the AvastVBoxSVC ( http://malwaretips.com/threads/avast-ng-what-is-it-avast-2015.35640/ ), I concluded that this is a feature that I don’t want or need bogging down my system. These features might make sense for the average user, but as an informed power user who has worked in IT for 15+ yrs and never had an infection on my personal computer, I hate bloated crap like this. The File, Mail, and Web shields are good enough for my purposes, based on the fact that I don’t visit untrusted sites, click random links, download files from untrusted sources, etc. NG is a good idea in theory, but not if it is going to degrade my system performance.
I went to Control Panel => Programs and Features, found Avast Free Antivirus in the list and clicked “Change”. I unchecked NG and some other default features I didn’t want or need and then clicked “Next” to uninstall those features. After a reboot, my system seems to be running a lot better and a lot more RAM is available.
Note: please be sure you run all uninstall and cleanup utility as administrator and - which is very important! - you rune it AS ADMINISTRATOR. Be an administrator and run something “as administrator” is not the same so you should do right click on a exe file and choose "Run as Administrator"option.
restart and delete manually both avast folders. One in Program Files and one in Program Data.
Then check if in the adapter properties in control panels → network adapter settings is not present “avast firewall NDIS filter miniport”. If yes, remove it manually please.
Then go to Windows\System32\DriverStore folder and search for aswndis*.* . If there will be anything with this delete it manually.
and install it. Before operating system restart go to avast GUI → settings → tools → Customize setting of avast safezone and reset Safe Zone and you may reset Sand box too.
After successful installation could you double click on you license file to register your copy of avast.
Just want to add that I had a few times laptop slowgin down to unusability in the last days.
I just now had a look at it instead of directly rebooting, and it was avastvboxsvc.exe that was destroying my laptop.
Why does that service exist anyway, I use VirtualBox to run some Linux box on my Windows 8 laptop, but the whole concept of that is compartimentilisation. How difficult is it to get that concept? It means host processes should NOT be interacting, or trying to do that, with the VM.
Can I disable that silly process?