stands for Samsung Phone Backup Message (or sometimes Samsung Backup File). It is a proprietary archive format used exclusively by Samsung Smart Switch —Samsung's official data transfer and backup software for Windows and macOS. When you back up a Samsung Galaxy device to a PC using Smart Switch, the software packages your data into files with the .spb or .spbm extension.
If your goal is to generate shareable VCF links from contacts you've already extracted: spbm file to vcf link
If the SPBM file uses commas, tabs, or pipes ( | ) to separate data: stands for Samsung Phone Backup Message (or sometimes