Since a recent-ish update (deferred rebooting to update for a bit) to Avast one of my machines has decided to go on a slow down, turns out AVASTSVC.EXE was using 70 - 90% CPU and close to 1.5GB of RAM.
Disabling the shields helped a bit, CPU usage went down to 20% but RAM stayed, I have had to disable the service for my machine to be usable, not ideal obviously, but the fan noise was becoming unbearable.
I am using Avast Free, Windows 7 x64 and there are no other virus scanners etc installed and nothing has change in the last few months that would cause this, Chrome has done a few updates that's about it.
What is going on? This isn't the first time this has happened, and I had to roll back to a previous version and block updates for a while until it was resolved previously.
I have had to already remove the behaviour shield as it made the machine so unstable it just used to lock up until I forcibly rebooted it.