The .part1.rar suffix indicates this is the first segment of a multi-part compressed archive.
Scrambled names are frequently used to hide viruses or Trojans. RsrorosidHneEATRD92emnL00Buax6-D32.part1.rar
The string is likely a base64 variant or a randomized hash. RsrorosidHneEATRD92emnL00Buax6-D32.part1.rar