IDP.Generic or any other generic detection I would say has a lower standard, given the use of generic methods (not being specific).
I’m not sure how the other scans at VT go about checking the installer, the ones where it timed out are probably trying to unpack it to do a thorough scan of what would be a packed executable.
Possible False Positive - New location to report both a False Positive and or a False Negative (for File or URL)
You won’t get a direct response but it should be analysed within 48 hours, if found to be false it will be removed.
When you get an Avast Alert, expand it to Show Details and there should be a means to report a possible FP there also.
If the file was sent to quarantine you could also submit it from there.
I just want to add that avast is NOT identifying the static file as a threat (i.e scan or when installed), but only it’s behaviour when it is executing.
If you have the image on your desktop, when you get to the point to inserting an image, just use windows explorer to drag and drop the image into the post (not attaching as that is restricted).
That way, it keeps it in the topic and no one has to click an unknown external link to see the image.