Try Harder! My Penetration Testing with Kali Linux OSCP Review and course/lab experience — My OSCP Review | by Jason Bernier

Introduction:

Obtaining the OSCP certification is a challenge like no other. After my experience with the OSCP exam and course from Offensive Security, I decided to go ahead and write an OSCP Review. I decided to take the OSCP course and exam in September 2014 after seeing some fellow members of a forum I frequent quite a bit (www.techexams.net) state that they were taking it soon. This is a course and exam I wanted to tackle as I have a passion for IT security. I figured why not sign up as the same time and compare notes etc with like minded people, and make the process easier.

So I signed up, for the 90 days, and a week later, I was sent the introduction email with all the information I needed to connect to the Offensive Security labs via VPN, IRC information, login information, and forum information.

About me:

I have about 20 years of combined IT experience. I have two MCSEs, two MCSAs, MCITP:VA, VCP5, Security+, CEHv7,  RHCSA, a BS in IT security, and I am finishing up my Masters in Applied IT with a concentration in Applied Cyber Security.  I currently work for Lockheed Martin as an Active Directory Engineer on a government contract.

The course:

When I first signed up for the course, I quickly went through the manual and videos that included with the email once you start the course. A lot of the information I was already familiar with as I had to review a lot of it for the CEHv7 certification. As we all know the OSCP exam and course are very technical and very hands on. The CEH is pretty much all about theory and multiple choice questions. I was glad to take a course that not only talked about tools, but how to use them, and why they are used.

So when I first started the course, I was very motivated. The very first day I was in the labs, I was able to knock out 3 servers with very minimal effort. At this point I am thinking to myself, this is too easy! That is, until I met “sufference”. Over the course of the next month or so I was able to get to about 20 servers. As I said in the beginning I was super motivated, but as time goes on, I was losing interest, and just simply didn’t have the time.

Sufference
As I said, I thought this course was too easy at first, and I was able to knock out server after server. That is until I met sufference. This is where I lost a lot of motivation. I believe I spent 3 weeks alone on this beast of a server. It demotivated me and made me feel like a child who just had his ice cream money stolen by Vic the bully down the street. I spent hours a day on this server alone obsessing over it. I decided to come back to it. So I move on to some other challenging servers and I am able to root them and get some of my confidence back.

I decide to go back and kick sufference right in the teeth after this. I do a lot of googling, AND I MEAN A LOT, and finally I find a way in and get a limited shell! Great! Half the battle has been won! This is not enough for me, I need to make this server my bitch and show it who’s boss. Yeah… not so much. Again I decide to regroup and move on…. maybe the answer will come to me. I pop a few more servers (at this point I am close to my 90 day point. I HAVE TO OWN THIS BEFORE MY LAB TIME IS UP!  One more attempt I tell myself.

I finally come across something that clicks for me, and I have one of those AH-HA! moments. Its something I should have seen sooner… but for some reason I did not, and stayed ignorant. I finally found the answer, and I was able to root sufference after nearly 3 months! My motivation and confidence have been renewed.

/sufference

I decide to extend for another 30 days. I only have about 30 servers owned at this point… and I hadn’t unlocked any of the other networks. I can do better. So I renew and I decide my new goal is to at least get into the admin network. After a lot of time spent in the labs and researching exploits etc, I had finally learned how to pivot into the admin network. Thank you proxy chains! I was able to get all of the servers in the IT network, and all but one in the admin network. My time was almost up in the labs, so I decided to go ahead and book the exam. I felt I was ready and could do this.

The Exam (part 1):

The exam is a 24 hour challenge. This means that you have 24 hours from the time the exam starts to try and compromise the servers assigned to you in the exam. Additionally you have another 24 hours after that to write your report and send it in for grading. You are graded on your report alone, and you HAVE to complete this in order to pass the exam. You are also encouraged to submit a lab report documenting your efforts in the lab. You may get extra points for this should you need them on the exam. This is all explained in the exam email.

I booked my exam for a Saturday evening starting at 5pm.  The email comes right at 5pm. I connect to the network, look at the exam guide that is provided and start working. In the first hour I had managed to root 2 servers. I felt like I was on a roll, and that I was going to end this beast early. Not so much.

After the first two, I didn’t get anything on the next three servers for the next 12 hours. Nothing. Zilch, Nada! I was deflated and dumbfounded. I figured I should take a nap and come back to it. Maybe I am just exhausted and needed some rest. I take a 3 hour nap and come back. This is what I needed. In the next hour or two after that, I had 2 more limited shells. I couldn’t escalate. I tried until the bitter end. At the end, I had two fully compromised hosts, and 2 limited shells. Would this be enough to pass the exam?

Turns out it wasn’t. I got the email Tuesday afternoon stating I hadn’t passed.

I will NOT be defeated!

The Exam (part 2):


I decided to extend my lab time for another 15 days, and book the exam 2 weeks after I had failed. I decided to concentrate on privilege escalations since this is what I was felt I was weak at. I spent the next couple of weeks working on that as well as buffer overflows. I really didn’t too much in the labs, except maybe a few servers I may have missed in the public network. I just really wanted to work on escalations. Turns out this was a smart move on my part.

This time I book the exam for 10AM. Again the email comes, along with the exam guide and instructions to connect in. Away I go. Again, I get the first 2 servers in the first hour. I don’t get a head of myself and just keep plugging away. I start on the next server and it falls in the next hour. By the 5th hour I had 3 full compromises and 3 limited shells. I KNOW I have passed at this point, by the amount of points I will be awarded based on the exam guide. Again… this is not enough for me. I have to prove to myself that I can TRY HARDER!

I do just that.

After 6 hours in the exam, I feel like I am done. 4 full compromises out of 5, and the last server I had a limited shell. This should have been about 90 points. I am satisfied but tired. I was smart enough to document everything as I went, so I only had to spend another hour fixing up my report. I sent my report to the offsec team, and walked away from my computer like a boss.

boss

Wrap up:

This is by far the most challenging and rewarding course and certification I have ever taken. I respect anyone else who has the guts to take this on and succeed. It truly shows you know your stuff in this field.

I sent off my report Saturday evening around 4-5PM. I got the response this morning (Monday Feb 23, 2015) that I had passed the exam. I am elated that this challenge is over and I was able to overcome it. I tried harder when it mattered most and I was able to accomplish what I set out to do.

I am now an Offensive Security Certified Professional because I tried harder!

oscp-certs

I can not say enough good things about the OSCP course and exam. I was challenged and I learned a whole lot more than I thought I would about security and penetration testing. I hope that the OSCP will gain more recognition by companies. The OSCP is the certification I am most proud of by far.

Time to update the old resume to reflect the new OSCP certification!

 

Resources:

Some resources I used for this challenge:

http://www.fuzzysecurity.com/tutorials/16.html
http://pentestmonkey.net/category/cheat-sheet/shell
https://github.com/GDSSecurity/Windows-Exploit-Suggester
https://github.com/PenturaLabs/Linux_Exploit_Suggester
https://blog.g0tmi1k.com/2011/08/basic-linux-privilege-escalation/
http://www.offensive-security.com/metasploit-unleashed/Main_Page

I also read the hackers playbook, the Metasploit unleashed book, and the Penetration Testing book by Georgia Weidman.

These are all very good resources.

Thanks to all those who helped me and pushed me when I needed it, especially all the other people who have written an OSCP review to help others.

More information about the OSCP and PWK can be found here:

https://www.offensive-security.com/information-security-training/penetration-testing-with-kali-linux/
https://www.offensive-security.com/information-security-certifications/oscp-offensive-security-certified-professional/

Good luck to anyone wishing to take on the OSCP course and exam. After you pass the exam, write your own OSCP review!


This post was originally posted on: Blog of Jason Bernier

 

December 10, 2015

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janespa
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janespa

Congratulations on your accomplishment. It is good to know that there are Certs that actually test hands on knowledge as opposed to multiple choice questions. I myself am looking at the two certifications that I feel are necessary for my business and that is both the CEH and the OSCP. I do hope as well that overtime the OSCP will be acknowledged as for what it is.

Thanks for sharing your experience and resources.

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