You got in! Congratulations! We all heard Griffindors saying the password too loud. Only the real one knows that

the moment password is said out loud or shown to other people then just to those, who shares them, it becomes invalid

Anyways, you grab Crabbe and return with him to Goyle.

As a thank you, he gives you a piece of parchment paper he stole from Gryffindor's Common Room, as both of them run away.

Staring at the parchment paper, you realize it is the

Marauder's map

Thankfully you heard of it before, so without hesitation you pull out your wand and say 

"I solemnly swear that I'm up to no good"