It’s been a couple years since, but I’ve installed and tested two native AV solutions — McAfee and Sophos. Both performed well enough and I have no major issues with them. I believe that Bytware’s StandGuard AV is built around McAfee and it seems to do well at managing AV activity and integrating with day to day system use. (We wanted to understand the market/technology, but we didn’t see sufficient ROI to pursue.)

Other solutions can be made to work. I think a few have even managed to get ClamAV going. The value-add for a product such as StandGuard AV comes in the GUI control and the automation that’s provided for downloading/installing updates plus the links through the OS/400 registration facility that allow automatic scanning of IFS files when opened, etc.

You can go open-source if you wish. Anything that can be made to run under Linux on PowerPC or AIX can be made to run on iSeries; that includes McAfee, Sophos and possibly others. Or you can go with a product designed for OS/400; StandGuard AV is the only one I’m aware of.

Technically, you can also go with any solution that can access shares across a Windows or a NFS network. This might be run from a cheaper Windows or Linux server or an integrated server card and would access only directories that have been shared. An obvious downside is that this would only cover basic scans and would not cover files as they are opened or written.