Trust but Verify.
Depending upon Windows or Linux for your Server and what kind of Control Panel is used for the Hosting part, verify yourself that certain things have been done. Regardless of who installs what, there is always a way for others check on what has been been done and how well it is working. That's how Hackers get in.
Better protection can be provided at the Server level which is why that is so important. As to Security at the Hosting account level, make sure directory & file permission are what they should be. If any script, Zen Cart or otherwise, says that directories or Files need wide open permissions (777 for example) then make sure security has been put in place to help prevent hacking / cracking.