This problem has multiple parts:
- Find that the encrypted file is a png, and open it
- Understand the small-step semantics on the image
- Basically it says that the "flag" feature of the language reveals a flag when there are globally defined variables "username" and "password" set to root and the proper password
- The proper password can be found hidden at the end of the hex in the encrypted file
- Enter the appropriate things into the repl while nc'd to the server
Done!