Trying to generate an Undetectable Backdoor

hey guys! i’m trying to generate an undetectable backdoor with veil for windows computers using a MITM-Attack and inject it through a fake update but all my backdoors so far get detected by the default windows defender. i tried to use some services like nodistribute.com or antiscan.me to scan the file for known signatures in the databases of antiVir programms but those services are not working for me. they also dont include the default windows defender.

are there any services which work and include the signature database of windows defender?

peace

I am not an expert on making undetected backdoors,but have you checked if windows defender also uses AI to detect backdoors?

The implementation of an AI would change the rules for sure but it doesnt seem that way. The services are up and running again. The database of windows defender is also included.