avast does not detect MSieXec64.exe

please check into this.

Have you turned ON PUP detection? (Default off)

https://www.virustotal.com/#/file/84dd02debbf2b0c5ed7eebf813305543265e34ec98635139787bf8b882e7c7b4/detection

hmmm, i guess not since i did not know i had to allow my scanner to search for certain virusses in the settings menu.

could someone explain me why this isn’t standard?

Legal issues, you need to turn it on yourself.

PUP are not virus, PUP = Possible Unwanted Program (wanted for some, unwanted for others)