The 15949.mp4 file from the Cyber Apocalypse CTF 2022 "Reflection" challenge is a Windows memory dump requiring analysis with Volatility 3 to uncover a hidden flag [1]. The investigation typically involves identifying a .NET reflection technique, extracting files using filescan and dumpfiles , and decoding a script to reveal the flag [1]. You can read a full walkthrough of the process on Cyberdough.