Akeeba Backup is an extension for backup management. It is the industry standard, a JED's TOP Rated and MOST Reviewed extension. 

It almost has no interaction with the front-end site. If there were any vulnerability, it would be reported immediately and I am confident that the author would fix it in the shortest possible time.

Artur Stępień's answer in [How to transfer a joomla content to another server?](https://joomla.stackexchange.com/questions/14355/how-to-transfer-a-joomla-content-to-another-server/14406#14406) is basically a recommendation to avoid any backup extension... because they are "generally" insecure and particularly he fails to include any real reference to a known vulnerability. So... you have to trust in Artur Stępień opinion.

Disclaimer: I am an Akeeba's customer and I have been installing Akeeba Backup and Admin Tools (for protection against hackers) in every site since I can remember.