I've already answered this question a few times here. Have a look at this answer in particular:

[Virus scanner on server](https://security.stackexchange.com/a/53462/2264)

And in particular this part:

> **The *concept* of a virus implies a user at an interactive session.** Someone opening email in Outlook or documents in Word, or running programs they received in an email. A virus implies a human element. Servers don't (or shouldn't) allow reading emails and browsing websites. Instead, attacks against servers are fully automated; no human required. They call that a "worm" rather than a "virus".
>
> Worms *are* a concern on Linux. **But protecting your server from that type of threat works differently.** Protecting users from viruses requires something stopping users from doing things they shouldn't. Hence the "anti-virus". But protecting servers from worms and similar exploits involves fixing vulnerable software. If something is exploitable on your server, then the thing needs to be fixed.

A virus scanner watches files to see if they will hurt you if you run them. That's not a concern on servers because the only programs you're ever going to run *are already there*. As a rule, you're not downloading and running new programs on servers the way you do on desktops.

Assuming Linux is running as a server, (which RHEL pretty much *always* is) **Running an anti-virus is the wrong kind of protection**. It protects you against threats that can't hurt you, while ignoring the threats that can. This is why RHEL doesn't offer antivirus integration. Because Redhat understands server security.

This has nothing to do with how popular Linux is or whether virus writers will target it, as commonly argued. This has to do with how the server is used. There is no user browsing email in Outlook, or download flash movies and running them. So preventing dangerous user activity is not a valuable solution.

If your QSA is demanding you run an anti-virus on your Linux server, then you need a different QSA. This one hasn't a clue.