If you want to know why a particular sample isn't detected please submit it to McAfee Labs via the instructions on the 'submit a sample' link on the threat center here:
See KnowledgeBase article KB69109 - Archive scanning support for 7-Zip (.7z) files
Thank you but seems I'm not able to find article KB69109 . the maxmum number of
KB is KB68787 :
search by title "Archive scanning support for 7-Zip (.7z) files " was not able to find the article either.
My sincere apologies for the inconvenience. It turns out this article is being updated. It should be available by close of business today. It basically states the following:
Scanning 7-Zip (.7z) archives is currently not supported. McAfee are looking into including this in a future Engine release.
This article will be updated as new information becomes available.
I would suggest adding the article to your favourites as soon as it is published, this will enable you to periodically check what the state of affairs is.
KB69109 has now been published. This article will be updated as information becomes available.