Using randomized strings instead of descriptive names (like "Wedding_Photos.rar") is often done to prevent automated bots from scanning and indexing the content.
Here is some interesting context regarding files with these kinds of names: 1. The Mystery of Split Archives sc20390-fh5updv1444438-part2-rar
The string sc20390-fh5updv1444438 is likely a or a job ID from a server. Using randomized strings instead of descriptive names (like
Breaking a 50GB file into 1GB chunks to make it easier to download without a connection failure ruining the whole process. sc20390-fh5updv1444438-part2-rar