How do I make sure my macbook is not hacked?

I was using google chrome to watch a documentary in youtube, however suddenly the video pauses by itself, decreases its video quality even though the internet was still sufficient for the video quality, and the video entered fullscreen by itself.

Checking activity monitor I saw that my mDNSresponder has 1,3mb sent bytes and 7,7mb received bytes.

Could this mean my macbook is hacked?

Also on a side note as I went to the apple website the top dock with the product menus would start stuttering, disappearing and reappearing periodically. I also scanned using the free version of malware bytes and other malware detection such as avast and sophos but there weren't any threat results. Still, the random occurrences and random freezing with low cpu usage when watching a video on youtube makes me question my laptop's status.

MacOSCatalina 10.15.2