Hi and welcome to avast,
If avast has such a feature, it sure slipped right past me.
It sounds more like some kind of anti-spyware you're also using, or possibly even some spyware or other malware itself has gotten into your system.
What other security programs are you running? I'd suggest they'd be the first place to look, both for their own settings and also to check whether you've maybe picked up a "friend" you don't want.
Best,
Mike