If you have an unencrypted version of one file inside the zip, use bkcrack to recover the internal keys and decrypt the rest.

The flag is often in the format flag... or CTF... .

Start by gathering information about the file without modifying it.

Look for images (steganography), text files, or hidden scripts.

If the file is password-protected, common CTF tactics include:

Provide those details so I can narrow down the solution.

Extract the hidden flag from a potentially password-protected or obfuscated zip archive. Difficulty: Intermediate (estimated) 1. Initial Enumeration