Autoit is far from just a macro builder. If you want more information on why it is getting flagged, or what to do about it, then please visit Are my AutoIt EXEs really infected? - General Help and Support - AutoIt Forums
Autoit was the third language that I had learned, and I still use it today. I do not go to the forums anymore, but that is for a more personal reason.
You ask for an explination... Well, it is amazing for automation tasks but can also be used for advanced development.