The VST53C-4MB-M.BIN file has been reported to appear in various locations, including:
: Power off the board and remove the USB drive before restarting. Critical Risks and Tips vst53c-4mb-m.bin
I’ve tried binwalk and file on it – no clear magic bytes so far. Hex dump starts with 00 00 01 00 ... but nothing obvious like a FAT or ROM header. The VST53C-4MB-M