Since you use Redhat, you should be able to download a .rpm and install that. RPM is Redhat Package Manager or something like that. In GUI, just click on it and give root password and it goes to installin.
Virus software. I use f-prot from, you guessed it, www.f-prot.com
. It is free for home use, pay for commercial stuff. It is on the site what is what.
I do this command to scan everything mounted:
You can leave off the -list if you don't want the list of scanned files.