Depending on what you are looking for, here are a few likely "contents" for a file with that name: 1. Gaming & Mods
If you downloaded this from a public forum or file-sharing site, always run it through VirusTotal before opening.
If you are into gaming (like Skyrim , Fallout , or The Sims ), "Anna" is a very common name for:
A file named is a compressed archive (7-Zip format), and without knowing the specific context of where you found it, it usually suggests a sequel or a secondary part of a collection.
Knowing the source would help me give you a much more specific answer.
Often used by photographers to batch-send files to a client named Anna.