Advice Request Does this prevent 3rd Party Security Apps from being installed on Windows 10?

[Ink]

I'm not one to switch security apps on a daily basis. Can anyone confirm if this a October 2018 Update feature, or based on the following Windows setting below.

Here's my current Installing apps mode, can be found at Windows Settings > Apps > Installing apps.

Spoiler: Set as:

Drop-down: [Warn me before installing apps from outside the Store]

I noticed when I ran some* Security Vendor installers *.exe, I received this warning:

Spoiler: It reads

You're already protected against viruses and other cyber threads with Windows security

[Check your Windows security]​

[Install anyway]​

[Change my app recommendations settings >]​

Tested with installers from * HitmanPro, Kaspersky Security Cloud Free, Bitdefender Free Antivirus

For comparison, if apps are downloaded from the Internet*, this is the usual warning:

Spoiler: It reads

The app you're trying to install isn't a verified app from the Store
Installing apps from the Store helps to protect your PC and keep it running smoothly.

[Get app from Store]​

[Install anyway]​

[Change my app recommendations settings >]​

Tested with installers from * CCleaner Free, AVG Setup, Avast Free, Avira AV

** I am not looking to disable this setting **

About This PC:

• Edition: Windows 10 Pro 64-bit
• Version: 1809
• OS build: 17763.379
• Antivirus: Windows Defender Antivirus

 

[ForgottenSeer 72227]

I m 99% sure it's based on that setting. I'm pretty sure that it block virtually all installers regardless of vendor, if it's not from the app store, using that setting. Unless they have a small whitelist for some vendors, hence the different prompt?

Another thought after posting, is maybe it uses mark of the web as well? If you use an installer from a USB or something and not download it directly, you get a different prompt?

 

[Local Host]

I m 99% sure it's based on that setting. I'm pretty sure that it block virtually all installers regardless of vendor, if it's not from the app store, using that setting. Unless they have a small whitelist for some vendors, hence the different prompt?

Another thought after posting, is maybe it uses mark of the web as well? If you use an installer from a USB or something and not download it directly, you get a different prompt?

They both related, you don't get that popup whasoever on a normal Windows 10 Setup.