While labeled as an .mp4 (video), these files often contain executable code or scripts that run when "played" in a vulnerable media player or if the user is tricked into double-clicking a file that is actually an .exe with a fake icon.
Remove the email or file from your system and empty your trash/recycle bin.
The alphanumeric string 3rhmd1qyqcvp is typical of "polymorphic" naming, where attackers generate unique filenames for each recipient to prevent antivirus software from flagging a single known file name.
Email attachment or direct download link. Technical Analysis
If this appeared in an unsolicited email or on a suspicious redirect page, it is almost certainly malicious. Recommended Actions Do Not Open: Do not download, preview, or execute the file.
Use your email provider's "Report Phishing" or "Report Spam" button to help their filters identify the campaign.