Is your computer being remote controlled? Without using the proper tools, there is no actual good defense against advanced malware like Remote Access Trojans, Keyloggers, Ransomware, and even just good 'ol spyware from Big Tech.
You need network monitoring tools to check the outgoing traffic and then put rules in effect so you either get alerted or block programs on your computer that try to talk to some command and control on the Internet. This is the job of an outgoing firewall. And today we will introduce you to Little Snitch for MacOS and Glasswire for Windows.
Without using these tools you are helpless. Antivirus software will not help you. This is just an introduction.