This conversion represents export of contacts from Samsung Kies contacts backup files (.spb) and save these in a separate vCard file (.vcf, .vcard).
You can do this with Samsung Kies and its VCF/CSV export function, unfortunately, in some later version of the programs this function was removed. This leaves users that have old .spb backups in a tight spot with no direct way to simply export their contacts from .spb files without restoring whole backup.
If your version of Kies does not contain contact export function, you can always try some older version (Kies 2.x seems to work) that does not automatically update.
Unfortunately, Samsung does not offer previous versions of Kies, so you have to look on web for sites that cumulate older software.