3 questions for my Apple genies about some vulnerabilities, downgrade attacks, and avast software on a mac.

Rubyrubyapple wrote:

1. I know I know, you guys told me to get rid of my antivirus, but I havent yet. The reason is because I am so busy and I always feel like it’s going to be a huge process. Anyway, recently I looked into the Avast settings and there was an option checked that was “force all http3 web traffic to HTTP2 and HTTP to ensure we scan it for malicious software.”(Recommended feature) And I researched “downgrade attacks” and found this article explaining what a downgrade attack is. I am just wondering, does using this option also make me more vulnerable to the attack?

Uninstall AVAST. It is not needed and it may cause problems. It uses system resources while providing no benefit.

Effective defenses against malware and ot… - Apple Community

2. The other thing I wanted to ask is that I feel removing the antivirus software might be a task that I am unprepared for. Are there things that I should do in order to prepare for this? Like any settings that I will have to apply after I remove it?

Ensure you have a data backup before proceeding with the uninstall. There are no settings to be applied after the uninstall.

3. My third question for you guys is about the thunderbolt vulnerability. I do not have Linux or Windows installed, am I vulnerable to an attack if my attacker had physical access to my Mac? My ex who is a legitimate stalker has been able to break into my apartment and he has access to my mac. I am pretty sure he has hacked me at some point. I found out he did it to an ex and some of the things he had said to me indicated that he has been able to have access to my system. Also, he has a cyber security friend.

Any thought on any of these questions? Thank you so much.

If your ex has access to your Mac and password he can do whatever he wants to do. Change your Mac's password so that he can not access it. His "cyber security" friend can not access your computer if he does not have the password. Notify the police of his break in to your apartment.

Rubyrubyapple wrote:

1. I know I know, you guys told me to get rid of my antivirus, but I havent yet. The reason is because I am so busy and I always feel like it’s going to be a huge process. Anyway, recently I looked into the Avast settings and there was an option checked that was “force all http3 web traffic to HTTP2 and HTTP to ensure we scan it for malicious software.”(Recommended feature) And I researched “downgrade attacks” and found this article explaining what a downgrade attack is. I am just wondering, does using this option also make me more vulnerable to the attack?

2. The other thing I wanted to ask is that I feel removing the antivirus software might be a task that I am unprepared for. Are there things that I should do in order to prepare for this? Like any settings that I will have to apply after I remove it?

3. My third question for you guys is about the thunderbolt vulnerability. I do not have Linux or Windows installed, am I vulnerable to an attack if my attacker had physical access to my Mac? My ex who is a legitimate stalker has been able to break into my apartment and he has access to my mac. I am pretty sure he has hacked me at some point. I found out he did it to an ex and some of the things he had said to me indicated that he has been able to have access to my system. Also, he has a cyber security friend.

Any thought on any of these questions? Thank you so much.

Part 1 of 2

Any of the below should be removed as per Developers Instructions 

Third Party Security Software 

Avast AntiVirus

The below article is from a well Respected Contributor who specializes in macOS Security and related topics

FTC Order Will Ban Avast from Selling Browsing Data for Advertising Purposes, Require It to Pay $16.5 Million Over Charges the Firm Sold Browsing Data After Claiming Its Products Would Block Online Tracking 

FTC says despite its promises to protect consumers from online tracking, Avast sold consumers' browsing data to third parties

https://www.ftc.gov/news-events/news/press-releases/2024/02/ftc-order-will-ban-avast-selling-browsing-data-advertising-purposes-require-it-pay-165-million-over

The Operating System resides in a Sealed and Read Only Volume that cannot be opened by the User nor by Third Party Applications.

The only Entity that can open and modify or alter this Volume is Apple.

Part 2 of 2

The steps in #1 below is predicated on the Offending  Application has been Removed as per the Developers Specific Instruction 

# 1 Some Contributors suggest restarting in Recovery Mode and choosing to Reinstall the Operating System over the existing installation. 

This may or may not replace elements of the  Home Folder ( User Account )  and replace any corrupted or removed elements and make things right.

#2 - Then there are Other Contributors ( like myself ) would suggest  from this link Use Disk Utility to erase a Mac with Apple silicon.

For Intel computer >> Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS

Thereafter to start from scratch and install all Required Applications directly from the Apple Apps Store or Directly from the Developer.

If going this route - I suggest Not using Startup Assist to migrate things back as this will probably Re-Introduce the existing  issue at the time TM Backup was made 

Great advice so far, I consider Avast among the worst.