The file has likely been patched to remove region locks, allowing it to run on any 3DS console regardless of its original region (e.g., PAL or JPN).
"Ziperto" refers to a well-known third-party repository for Nintendo console ROMs and homebrew software. Important Technical Notes MHG-USA-CIA-RF-Ziperto.part1.rar
You must have all parts (e.g., .part1, .part2, etc.) in the same folder before extracting. Extracting just part 1 will result in an "unexpected end of archive" or missing data error. The file has likely been patched to remove