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.
: Use a Python script or a bash loop to extract until no more archives remain. 11-20.7z
: 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 While there isn't a single famous global CTF
The first step is always to identify what you are dealing with. Using the file command in Linux or a hex editor like 010 Editor helps verify the file header. : file 11-20.7z Step 5: Final Flag Submission The first step
: Use 7z l -slt 11-20.7z to view technical details and comments that might contain hints. Step 3: Handling the Recursion (The "Nested" Problem)
: 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.
The flag usually follows a specific format, such as CTF... or flag... . : CTFn3st3d_z1ps_4r3_fun_12345