Treat any file from a "mega" or public channel like a stranger. If you did not intentionally join the "@badgirlsmegas" channel, proceed with extreme caution.

Telegram Video Downloader - TG Downloader - Chrome Web Store

Historically, some vulnerabilities (like "EvilVideo") allowed attackers to disguise malicious .APK installers as .mp4 video previews. Always ensure the file extension is strictly .mp4 and do not install any software if prompted to "update your player" to view the content.