An extra indication that this Event Viewer error is Avast related: if I try to chnage anything in the service AvastVBox COM Service (which might be related to VBoxAswDrv mentioned in the selfdef.log of Avast, though I'm not sure) the same error appears in the event viewer. In the seldef,log the message is slightly different as it is refering to AvastVBoxSvc instead of VBoxAswDrv.
But the question remains the same: how to resolve the error messages?