FitGirl repacks are generally safe from malware, but because you are downloading from third-party torrent sites, always:
On systems with limited SSD space, users can install only the campaign, keeping the installation lean.
with the file present in the folder to install those assets. MD5 Mismatch:
Because .bin files are compressed and encrypted, they are often a point of concern for security-conscious users. In reputable repacking circles, these files are accompanied by MD5 or SHA-1 checksums. The installer typically runs a "QuickSFV" check to ensure that fg-optional-multiplayer-build.bin is not corrupted. If the binary data is altered by even a single bit, the decompression will fail, protecting the user from a broken installation or potential "data rot." Conclusion
file contains data specifically required for the multiplayer portion of a game, such as maps, player models, or dedicated networking code. User Choice
If you are a data hoarder or archivist, you might want to keep the file for completeness. However, note that fg-optional-multiplayer-build.bin is often the largest file in the repack. Keeping it on a backup HDD is fine, but including it on installation media for friends who only play single-player is wasteful.
The file fg-optional-multiplayer-build.bin is neither malware nor a mystery. It is a highly compressed, optional archive of multiplayer data created by the FitGirl repacking team. Your action plan should be: