What app is causing this... Phishing issue

Also remove the Virus Barrier Scanner. It is just as useless as the AT&T Smart Home. The purpose of these notifications is not to protect your Mac, it is to make them appear to be useful so you will continue with the service making you feel like it is doing a good job.

If you are interested in the extensive steps Apple takes to maintain Security, you can read this Support Article to understand the lengths that Apple goes through. You will not find any additional software that is going to protect you further.

https://help.apple.com/pdf/security/en_US/apple-platform-security-guide.pdf

It’s typical useless tech by AT&T - uninstall it (assuming there’s no setting to disable). They know nuthin’ about Cyber.

It’s the amateur AT&T app screaming thief just for the heck of it - ignore, not worth pursuing. Your iMac is all you need for security: everything else is a virus.

Separately, go through the Privacy and Security settings on macOS and also your apps, and disable any that have been enabled by default - that’s what this is about.

Yes - any virus that gets you worried needlessly and makes you spread useless links even if simply asking why, has done half its work. Uninstall and forget, don’t be AT&T’s free virus messenger and don’t do its work.