To give you the exact contents, I'd need to know where you found this file (e.g., a specific Discord, a YouTube video description).
Here is a typical breakdown of content for a file named "A HOTRAIL.rar": 1. Audio Assets
One-shot samples (kicks, snares, hats) and drum loops tailored for Hyperpop, Glitchcore, or Trap genres.
.fxp files for Xfer Serum, usually containing heavily distorted basses, plucks, and leads.
This type of file is usually shared within underground producer communities (Discord, Reddit) for artists looking for a specific, modern, distorted sound signature.