Run file CTESP.rar to confirm it is indeed a RAR archive and not a renamed file (e.g., a JPEG or executable).
If it is from a specific university lab or a recent CTF, I can provide more targeted steps based on the known "hints" for that specific event. CTESP.rar
If this is a challenge you are working on, here is a general forensic write-up structure and the most common steps you would take to solve a challenge involving a compressed archive. Filename: CTESP.rar Category: Forensics / Cryptography Run file CTESP