The SPD executable, Spd-v1.0.4.28.exe , is one of these installer files. It is hosted on HP's official FTP servers, accessible through a direct download link, further confirming its legitimacy as an official troubleshooting patch.
If you are trying to resolve a "link fails" error when downloading : Spd-v1.0.4.28.exe
: It establishes a handshake with remote servers to download and flash device updates automatically. The SPD executable, Spd-v1