The difference is that the attacker can make budget.pdf start with #!/bin/bash and immidietly have arbitrary code execution when I do "./budget.pdf" When I do

The difference is that the attacker can make budget.pdf start with #!/bin/bash and immidietly have arbitrary code execution when I do "./budget.pdf" When I do "evince budget.pdf" the attacker is required to find an exploit of evince.