How to know if my Mac M1 or iPhone is being hacked?

CSSC33 wrote:

I’ve had a hacker in my Mac M1 and IPhone for 8 months. I’ve wiped my Mac many times as well as the phone. I even changed my service provider. Does anyone have any thoughts!

Why do you think you have a "hacker"?

Writing an effective Apple Support Commun… - Apple Community

And perform a clean install of the OS of all affected devices which involves erasing the device followed by reinstalling the OS.

Do not restore from a backup since you may bring something back. Manually transfer your data files back to the clean OS on each device & manually download new copies of your third party apps & install them. I would also get a new backup drive to start with clean backups....keep the old back drive handy just in case you missed transferring any documents or if you need an older revision of a particular document.

Like the others mentioned, it is unlikely for people to be hacked unless they fall for a phishing scam, or download software (sometimes even document files) from any source other than the official vendors' websites, or allowed someone to access their device. You may want to review the following article which will help keep your devices running smoothly & help to keep you & your devices safe (greatly minimizes chances of something bad anyway)....make sure to read each linked article within this article as well:

Effective defenses against malware and other threats - Apple Community

Depending on what has occurred, you may need to seek local assistance from a professional to restore everything to a clean state & to safely restore your data.

While the odds are you do NOT "...have a hacker..." in your Mac, we'd need more details on exactly what you're seeing that leads you to believe you've been hacked.

Regardless, the very first thing I'd do is change passwords if I suspected any account of mine had been hacked.