I can confirm that McAfee and Trend Micro do the same thing. McAfee even goes so far as to lock files in your AppData and Tmp folders until it's finished check

I can confirm that McAfee and Trend Micro do the same thing. McAfee even goes so far as to lock files in your AppData and Tmp folders until it's finished checking them. This causes havoc with a lot of apps and makes certain ones completely unusable.