Installing Anti-Virus on Availability Group databases
Theoretically, whatever box it's on shouldn't be doing to sort of activity that leads to virus and malware. If you follow that guide things for the most part should be fine to install the software but it will still be using some hardware resources.

I'd recommend you just follow the Microsoft laid path. You may also want to talk to the software vendor to make sure they don't have any specific recommendations. Beyond that just beware that the software will still have processor overhead as well. You'll likely not want to have SQL Server maintenance jobs at the same time as whatever scanning this virus software scheduled to run. - zane