The Locked Door… Do you think like a Social Engineer?

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The Locked Door… Do you think like a Social Engineer?



A while ago on LinkedIn I posted the following riddle and its answer. It got lots of interaction because EVERYONE when they put their minds to it, likes to think of themselves as a Social Engineer, at least some of the time!

Here’s a Social Engineering riddle, answer below.


A few years ago I found myself facing a locked door, which I needed to be open later that day to facilitate my entry and exit from a building. (Ask no questons, hear no lies….)

Now as any Social Engineer will agree, we rather expect this, it is not necessarily a bad thing and there are many ways to open a locked door. I would normally just ask someone to let me through and you would be surprised how often this works even with no badge, no recognition and no reason to be in the building!

However, on this occasion I would be at the door at a time of day when no one would be around so asking wouldn’t be possible…

Now, without the use of lock picks or tech of any kind I made sure the door would be open for me when I returned to the building the following evening.


The Locked Door….The Answer

“You can have anything you want if you are willing to give up the belief that you can’t have it.”

Robert Anthony


So how did I make sure that the door would be open for me when I returned later that night.


Well, good news is that once again quite a few of you managed to get the answer right, at least mostly, it was a no-tech con in two parts.


Firstly, I wrote on a piece of A4 paper in large red letters


“Please do NOT close this door!

Lock Broken, Vendor informed.

Thank you for your cooperation.”


However, I also called the security guard desk and said


“Hi, its (mumbled name) from HR just checking that you know about the lock company coming later?…oh right it’s about that bloody back door on the warehouse? They are on the way but we have to leave it open or it breaks, or slams OR something. [sigh]


Anyway, now you know can you make sure it doesn’t get shut accidentally for me, it’s a fire risk now. Two people have already slammed it shut earlier today, even though there is a clear notice on it. Cheers thanks, oh and supplier should be at the gate in an hour or two. Cheers”


Now, the piece of paper alone usually ensures that the door stays open, and very often I have just written “Leave Open!!” on it with great results. However, it is always as well to use a belt and some braces as well if you can in social engineering, and as the security on this site was fairly high I thought my notice could use a bit of help. I wanted the guard to expect something unusual, assume it was being dealt with and ignore it. It also prepped them to hear my “door supplier” story if they caught me later on.


That piece of paper is really powerful though and you might wonder why do people blindly follow words on a page anyway?


Well, firstly, if you right something down people are more likely to believe it than if you just say it. Theories abound as to why this is, and it is more likely to be the case in some cultures than others, but in a culture that uses contracts to enforce obedience, like the UK, USA, and much of the west, the written word IS associated with gravitas, rules and warnings. Good.




However, the truth as to why most people, regardless of culture, obey the notice is actually more simple than you might expect. You see, that little sign makes them blind, deaf and disinterested. That sign, in the words of the late Douglas Adams (shout out to Dr Danny Dresner), makes the door, and its associate problems “SOMEBODY ELSE’S PROBLEM” and as soon as you do that with practically anything you can almost guarantee a lack of interference.


People everywhere have several things in common and one of them, I can assure you, is the will for a “quiet life” in terms of their routine, even if they are an extreme ironer or whatever, in their spare time, when they are in auto mode they do not want to be disturbed.


People like their routines, and, when operating within them are blanketed by the comfort zone of the familiar. “I’m in my automatic mode, please don’t disturb me” is the rule of thumb and thought process prevailing. Therefore, a faulty door, especially one that is already being dealt with by someone else, will not wake them from the slumber that most of us are in when operating within the routine. Even if they notice the unusual, they will mostly just be grateful that it is being sorted by someone else and is NOT THEIR PROBLEM, and if you throw in the implication that the “vendor” has been summoned to deal with it, then they will raise their brows to heaven, tut quietly at the incompetence’s of the world and…





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Posted in Social Engineering, The Deception Chronicles
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