Rahal is a Division agent.
In the "Resistance" Alex is being evaluated on how to interrogate someone. Her assignment is to interrogate a supposed Egyptian terrorist known as Bashir Maro. But as she refrained from torturing him, Bashir slips out of his bonds and attacks Alex before the agents outside could restrain him.
It is later revealed that Bashir Maro is in fact a Division agent known as Rahal.