These files are generally found in community forums focused on satellite TV receiver software (like Digital-Kaos or similar European satellite forums), or on third-party firmware aggregation sites.
Installing incorrect or unauthorized firmware can permanently damage ("brick") your device. Always ensure the file is specifically for the S410 model and follow instructions carefully. Download FTE MODEL MAX S410 rar
Such files typically contain a .bin or .abs file (the firmware/firmware upgrade) and a text document with flashing instructions [1]. These files are generally found in community forums