The generic alphanumeric name is a hallmark of files distributed via file-sharing sites (like Mega or MediaFire) or specialized forums.
Any or prompts you received when trying to open it? SPECIAL1014_PACK5.rar
Archives with "PACK5" in the name are frequently part of a split-volume set; it may require PACK1 through PACK4 to extract correctly. The generic alphanumeric name is a hallmark of