If it’s supposed to be a "high-def video" but the file is only 200KB, it’s almost certainly a script or a virus. How to Safely Inspect the File
If this was sent to you via an unsolicited email or downloaded from a site you don't trust, do not open it. Trest12.rar
Scammers often password-protect RAR files to prevent antivirus software from scanning the contents inside. If it’s supposed to be a "high-def video"