ZIP archive of about 261 KB tied to the ASUS X99-DELUXE desktop motherboard; the leading number looks like a catalogue index and the name does not reveal what the archive holds. At this size it is most likely a boardview or a compact service document rather than a full BIOS image, so inspect the contents after extracting. Boardview files open in tools such as OpenBoardView or FlexBV and let you locate components, test points and nets. Match the PCB revision printed near the board edge before trusting part locations.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @boardview. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.