In communities that share copyrighted material (leaked music, movies, or software), uploaders use "nonsense" names to evade automated "takedown" bots.
A user searches for a "cracked" version of expensive software or a "free" movie. Download File cwfbyt5fjxu2.rar
They click a link and find a file with a gibberish name. Download File cwfbyt5fjxu2.rar
It cannot find the movie if it is named "cwfbyt5fjxu2.rar." Download File cwfbyt5fjxu2.rar
Sometimes, these strings are generated by automated backup systems or private file-sharing tools.