Welcome to Android Central forums. Just a couple of quick questions.
Is this backup on your old device?
What are your plans for the old device?
Is the old device also a Samsung?
How you locating the file on the device? File manager, a settings tab or indicator which says there is a backup or some other way?
Not knowing your answers to my questions I will be making assumptions to offer some basic and generic advice. First if you are returning or fully decommissioning the device a factory reset should eliminate the back up as it should wipe all personal data from the device. Factory resetting the device should also void the encryption association between the card and the device. So if the backup is not removed for some reason the encryption needed to read the information will be lost making the data useless. If you do not intend to reset the device, although it is highly recommended, the use of a file manager, usually called File, My Files or File manager depending on the device, can be used to navigate to the folder and delete its content. If you cannot find the exact path, most file manger apps have a search function which, if the name you provided in your post is accurate, can be used to locate and delete the folder and/or the file within.
Let us know what you find and we can offer more advice with better information.
Best wishes