Generic PUA GI

The solution is to uninstall "Sophos" and never use it, or any other similarly categorized junk on a Mac. Follow its uninstallation instructions.

Please determine if the "AppNOS" process is in fact an active process. To do that, use Activity Monitor—it's in your Mac's Utilities folder. Post a representative screenshot of its contents, similar to the one shown under CPU in How to use Activity Monitor on your Mac - Apple Support. To capture, edit (if necessary) and post a screenshot to this site read the Appendix in Writing an effective Apple Support Communities question.

• If the "AppNOS" process or one of its variants are active then I can provide removal instructions that will work.
• If it is not active then there is nothing else you need to do.

This isn't the first time Sophos or other Mac AV software has flagged a process inside of a completely legitimate installer as a threat. Like the previous two similar posts I've seen on these forums, it appears to be a mounted .dmg volume named Installer, and the Installer.app within that.

I would assume you know what this installer is and ran Sophos to see if it was "safe". It may think this is a threat because it's part of an installer routine used by many apps. Such as the unwanted InstallMac adware. But it's also used (for one example, anyway), by iBoostUp, which is a completely useless "cleaning" app you can get through the App Store.

In other words, finding AppNOS isn't automatically bad.

Get rid of Sophos.

Gotcha. Several things occur to me:

1. sounds like the PUA GI is some segment or creation of the Sophos software

2. you can locate support for the Sophos software here: https://support.home.sophos.com/hc/en-us

3. Apple does not recommend running third-party antivirus software on macOS - the operating system already has antivirus software built in

4. Please let me know what you find out about the PUA GI. I'm as curious about this as you are.

Could you be more clear? What is a generic pua gi?

Get rid of Sophos.

It's not needed in Mac OS and gives you a false sense of security.

To reiterate, uninstall Sophos.