A company runs its production broker BRK1 with the broker administration security disabled. The company just found that one of the message flows stopped and was not processing any messages. While…

A company runs its production broker BRK1 with the broker administration security disabled. The company just found that one of the message flows stopped and was not processing any messages. While checking network logs, the security administrator found that due to a security vulnerability in the company, a third-party hacker managed to hack into the company's firewall and then into the broker from the web. What is the quickest action that the system administrator can take at the broker application level to stop the hacker with minimal impact on this production broker, while implementing a permanent way to secure the broker? Run the commands: