11-20.7z -

: If the archive is password-protected, look at the filename. In some CTFs (like CodeBattle ), the password is the Base64-decoded version of the filename or a string found in the file metadata.

Once you reach the final file (e.g., 20.7z or a flag.txt inside it), the flag is rarely in plain text. Common obfuscations include: 11-20.7z

Many "nested zip" challenges use a pattern where the filename itself is the key. : If the archive is password-protected, look at the filename

Flare-on 11 Challenge 5 Write-up — SSHD: | by Raviv Rachmiel While there isn't a single famous global CTF

: Check the archive's "Comment" section; flags are often hidden there to reward those who don't just "Extract All". Step 5: Final Flag Submission

If "11-20" implies a range, this file likely contains 12.7z , which contains 13.7z , all the way to 20.7z or flag.txt .

While there isn't a single famous global CTF challenge exclusively named , this file naming convention is a hallmark of forensics and steganography challenges where players must navigate deeply nested archives or "Russian Doll" files.