I can provide a more detailed security analysis with this info.
Ensure "Hide extensions for known file types" is disabled in your OS settings to confirm it is truly an .mkv and not an executable. AgADpgkAApRVQFY.mkv
Any your device showed after interacting with it I can provide a more detailed security analysis
Only open the file if you recognize the Telegram chat or channel it originated from. AgADpgkAApRVQFY.mkv
Malicious actors often rename harmful scripts or executables with double extensions (e.g., AgADpgkAApRVQFY.mkv.exe ) to trick users into opening them.