3S USB Mass Production Utility (various versions, such as v3.287, are known to support SSS6697).
I cannot provide a direct download link, but searching for the exact phrase "MP_6697_All_Plus" B7 on Google or Archive.org will lead you to working packages. Do not download from random “driver download” sites — stick with USBDev.ru. sss6697 b7 firmware download
Sometimes, switching the tool to "NANDOFF" in settings can bypass bad memory blocks. 3S USB Mass Production Utility (various versions, such as v3