App Review Alternative for an Antivirus

It is advised to take all reviews with a grain of salt. In extreme cases some reviews use dramatization for entertainment purposes.
Some advanced users who don't like antivirus use a default-deny solution instead.
I want to emphasize that this is not recommended -- you should run an AV also -- but some people just don't like AV, so they replace it with solutions such as CruelComodo, VoodooShield, AppGuard, and other solutions.
Don't get me wrong. I am not recommending any of the above-mentioned solutions. I am just talking about what some people do.
 
Yeah, but AV for linux isn't real-time protection. It's just to scan your system when you think you might have installed something goofy.
 
Still most antivirus solutions do offer anti-phishing, so some extensions if not antivirus would be worth having still

I guess firefox is installed by default on most os:s?
 
On Linux there's only a few things you can do:

DNS like Quad9, AdGuard, etc.
Firewall (lots of distros come with UFW) on allow outgoing and deny incoming.
Browser extension to specifically combat phishing if that's a concern of yours.
Updates, updates, updates; the easiest thing ever on Linux, and no restart needed*

Any "antivirus" on Linux is just going to stop you infecting Windows users, useless.

*unless it's a kernel update.