Malware Blocked Alert - can you tell me what to delete to resolve?

That message appears to be caused by Citrix Service Records item as noted by leroydouglas, but I also think com.Software-Updater.agent.plist looks sketchy. Legitimate apps may install and update service, but they are normally named for the company or app, not something generic and fishy like "Software-Updater."

If you are subscribed to or using some sort of third-party software aggregator website that keeps the apps updated, get as far away from that as possible.

SKRLion wrote:

You can uninstall Citrix...?

or contact their support

Citrix Support - Citrix.com

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS