Modern browsers block "mixed content." Your old http:// link would now be flagged as insecure. Even if the file existed, Chrome/Firefox would not download it without manual override.
aat8934 likely corresponds to an or TOEFL iBT preparation book, circa 2010–2012.
As we dig deeper, several theories and speculations emerge:
At first glance, http://barronsbooks.com/media/aat8934 appears to be a URL pointing to a specific media file on the website Barronsbooks.com. The URL is comprised of several components: