The media family on device ” is incorrectly formed. SQL Server cannot process this media family.
RESTORE HEADERONLY is terminating abnormally. (Microsoft SQL Server, Error: 3241)

This error occurs due to the following problems:

• Backup file is corrupted.
  
  The following post helps you verify your database backup: Verify SQL Server Database Backup
• Backup was taken on a higher version of SQL Server and restoration is being done on the earlier version.
  
  The following post gives you more details about this: restore higher version database backup on lower version sql server – restore problem

Fix:

• If you feel backup could be corrupted take the backup again
• If you are using FTP then use it in binary mode to copy the backup file into local drive
• If the versions are different then update the SQL Server on the system into which the backup has to be restored
• Verify the database backup to check what the issue is.
  Following post helps you verify your database backup: Verify SQL Server Database Backup

More about using restore verify only this option in SQL Server can be found here