The patent agent leaked the patent.

First of all, agents need to abide by professional ethics. If what you say can happen, it is illegal for the agent and may lead to serious imprisonment. If you really steal your patent, the examiner will search it in the examination of the invention application. If someone steals your patent, it will be found out to deny the patentability of your patent application, and you will know.

If you are worried, don't look for a patent agency. You can apply for it yourself. The state has no restrictions on this.

This society needs division of labor and cooperation, and how to inspect and find a suitable partner is also a basic skill. Not only patent application, business cooperation technology research and development, etc. All things may have similar situations, but we must measure the possibility of real occurrence. If everything is thinking that the worst will happen, then do nothing.