If this is a local file on your machine, you can check its basic properties using services like VirusTotal to see if it has been analyzed by others, or refer to general guides on how ZIP files work from Dropbox.

(e.g., finding a hidden flag, decrypting the contents, or reverse-engineering an executable inside).

If you have already run tools like file , strings , or binwalk , knowing those results would be a great head start.