“24B93E7F-8822-4465-B473-7BE7BB8E3E4A” will damage your computer. You should move it to the Bin

Since the system is modified, I’m not so sure we can even trust gatekeeper now. My answer below is still good advice (especially for people with 100% authentic macOS installations) but the waters are much muddier now that more details have come to light on this specific mac. Nothing wrong with system modifications, but they change expectations based on what specifically was disabled and changed.

With this in mind a scan by Malware Bytes is a very correct next step: https://malwarebytes.com/mac/

If the system can’t move the file to the bin, then you probably want to do an erase install. I might not reconnect a Time Machine drive if you already have a good backup from before this happened to be safe and instead connect a new drive and let the system back up.

You might even try booting in safe mode and applying all security updates and then boot again in safe mode to make one new backup to a new direct attached hard drive. This may prevent the periodic script that is trying to reinstall something bad from running.

At that point, you can erase the mac and then move your data back. The system is designed to eliminate a threat like this and if clicking the button doesn’t clean it - you need special skills, special additional software to avoid an erase install.

In the usual case this alert presents the name of a file or application, so you might try searching for a file with the name "24B93E7F-8822-4465-B473-7BE7BB8E3E4A" using a Finder search or a file system search app (I use Easy Find, freeware from Devon Technologies). Once you've found it, you can delete it.

Files with UUIDs as filenames are usually scratch files used by applications or the system to store data the user shouldn't be interested in. If one gets moved or corrupted it could trigger this kind of warning, I suppose. It's probably not anything explicitly dangerous, but to be on the safe side I wouldn't try opening it.