why would you need to do that, especially if you can't do it from the catalog admin app?
if you try via api - it will most likely be the same.
I am wondering about the use case here!.
You can cancel the job execution with the help of
'/1/catalog/resources/jobs/cancelcancelJobExecution' API. But you user account needs to have REST API privileges for the same.
Or, If you know the yarn application ID of the scanner job, you can kill it from the cluster machine using the following command.
'yarn application -kill <applicationID>'