Wednesday, December 18, 2013

Penetration Testing Interviews - Minimum Requirements

We have been interviewing a lot of people lately for penetration testing jobs. From the entry level through senior level. Unfortunately, most of the people we interview should not be interviewing for these positions at all. These are people that have made it through our initial company filters and yet we still have a lot of bad interviews. It is not the fault of our recruiters, rather the fault of the candidates that do not fully realize the requirements of a penetration tester.

Usually when one of these candidates sits down in a room, myself and my colleague can tell within a matter of minutes if they are full of shit, or if they have something to offer. After they pass the full of shit mile marker, the remainder of the interview is to really gauge their depth of knowledge. This post is a plea to potential candidates to satisfy a minimum set of requirements, which differ for each level of pen tester.

Generally, there are several things we (as well as other companies) look for in a solid penetration testing candidate. They must be technically sound, client presentable, have a strong passion for information security and fit in with the team.

Before I dive into each level and their respective requirements, one basic requirement that is consistent throughout all levels is this: Do not bullshit us. If you do not know an answer, just say you do not know an answer. If you even smell a little bit like bull shit, you will make getting the position close to impossible so just avoid it all together. While consulting is a bit of smoke and mirrors itself, you cannot bullshit a bunch of bullshitters. If you are planning on this tactic, your BS better be good enough to fool us. After all, if you sat in front of a client and BS'd your way through an answer and the client realized it, you would be in a tough situation. A client will never mind if you say "I am not sure, I will check with my team and get back to you on that." The only exception to this rule is if the interviewer says, "that's OK if you don't know the answer, how do you think that would work? Or, how would you approach it?" That is a question designed to see how you think, then it is perfectly fine to BS that answer.

Entry Level Penetration Tester, Minimum Requirements

We look for passion and technical aptitude at this level. Passion isn't just that "you love this stuff," prove to us that you love it. Do you have a blog? Awesome, show us. Do you have any personal projects? Awesome, show us. Do you play with vulnerable distributions? Perfect, tell us about them and what you did with them. Once we hired a guy because he showed us a picture of himself standing next to a bunch of Sun servers with a big grin on his face when he was 10. That isn't the only reason he got the job, but it helped his story. I often say that this job is more like a "jobby" - a job and a hobby. You get the point hopefully.

Passion is huge, but not the only requirement of an entry level pen tester. Here are the basic technical requirements... Know nmap enough to run it a few different ways. Know Metasploit enough to exploit a system, the differences in payloads and some of the auxiliary modules. Know the basics of Windows, Linux and networking. If you're not sure what to know here, then think like a hacker... For example, where are the passwords stored for each of these? A lot of pen testing can be taught but you are expected to come in with a basic set of skills. If you don't know what the difference between a /23 and a /24 network are, then you're not ready.

Mid Level Penetration Tester, Minimum Requirements

All of the above, plus you better understand a little more under the hood. A mid level person might really be an advanced entry level person or a someone that might be a senior, but we just couldn't tell for sure in the interview. They might need to "prove" they are a senior. Either way, there is a bit of a range in the mid level.

From a process perspective we're interested in how you would navigate a pen test. Do you have anything that resembles a methodology? Do you know how to use the information you gain from a system? You better know what pass the hash is, SQL injection, cross site scripting and what type shell you would use to get out of a network. Also, if you know this, you should know your favorite tool to do so and some of the possible switches with each. If you have taken OSCP, you should know all this already. In addition to these basics, a mid level pen tester is going to be on larger projects, likely client facing. Iron your shirt, don't wear birkenstocks and please pretend like you would be in front of a client during your interview so dress appropriately. A mid level pen tester should not need much training and should be able to hit the ground running pretty quickly.

Senior Level Penetration Tester, Minimum Requirements

All of the above, plus you better be an expert in something. Even better, be an expert in most things. you should be comfortable with the technical details of all kinds of systems. Most importantly, knowing the details about EXPLOITING systems. You should know about password cracking, exploitation of all kinds, pivoting, pilfering, lateral movement, privilege escalation and everything else pen test related. If you are not 100% familiar you should know enough theory to make a pretty educated guess. This guess I'm referring to is not BS as noted above, there is a big difference. Also, seniors are going to be put on the largest projects so you better be a good pen tester. You better know how to get some pwnag3 without a single vulnerability on a vulnerability scan. There is also a leadership quality here that is a major bonus. The entry and mid level guys will look up to you for advice and guidance, try to demonstrate that in your interview if possible.

My last plea for all positions is to get your OSCP first if possible. Every candidate that has their OSCP coming into the interview has a little bit of street cred and we can assume a certain level of knowledge is already there. Again, if you're lying it will come out very quickly.

I am on a quest to save everyone's valuable time, both yours and mine. Please understand that becoming a pen tester is a significant commitment and if you're at all casual or unsure about becoming one, you're not the right person for the job.


Μαρκοσ said...

What if a guy shows a picture with him and his family members standing next to a lamb roasting on a spit?

Craig said...

I would ask him where my damn lamb is. What's up Mark.

technologyfinder said...

how much can you earn yearly as a pen tester?

Craig said...

I've seen entry level as low as 35 and senior/principal as high as 200 (USD).

Unknown said...

Do you know somewhere i could get a more specific list? (other then want ads)

Unknown said...

This is awesome, Help a lot of people to understand interviewer & What actually pen test means?