where is the account to execute ssis in file system when run a job

Hi

I have a ssis package in file system, and create a job, in general... the section package:... select "File System".

but it thrown: access denegate: the user should be administrator..

what is the account or where is it, that use to run the job in agent, this is owner of the job?

this is my configuration..

http://blog.sqlauthority.com/2011/05/23/sql-server-running-ssis-package-in-scheduled-job/