OSEP review (OffSec Experienced Penetration Tester)

The OffSec Experienced Penetration Tester (OSEP) certification is designed for offensive security professionals who want to move beyond traditional penetration testing. Rather than simply focusing on gaining initial access, the course emphasises operating in hardened enterprise environments, bypassing modern security controls, maintaining stealth, and achieving objectives while simulating realistic adversary behaviour.

Overview

After passing the OSCP in 2023, I wanted to continue developing my offensive security skills. Because this aligned with my day-to-day work, I decided to start the PEN-300 course from OffSec in August 2025.

After several months of studying, completing the module labs, and finishing all eight challenge labs, I successfully earned the OSEP certification in June 2026. Looking back, every hour I invested was absolutely worth it.

If you’ve completed OSCP, PEN-300 feels like the natural next step. It introduces considerably more advanced offensive techniques while placing a much stronger emphasis on operating effectively within enterprise environments and adapting to common defensive controls. Throughout the course, you’ll gain hands-on experience with topics such as process injection, payload development, defence evasion, and advanced lateral movement.

I thoroughly enjoyed the course from start to finish, and every chapter introduced something new. Almost every topic is accompanied by a dedicated lab where you can immediately apply the concepts, experiment with payloads, and become familiar with the techniques before moving on.

Although OffSec describes PEN-300 as an advanced penetration testing course rather than a dedicated red teaming course, I believe it provides an excellent foundation for both penetration testers and red team operators.

In my personal opinion, OffSec offers some of the best hands-on offensive security training available today. That doesn’t take anything away from other excellent platforms such as Hack The Box, TryHackMe, PortSwigger Web Security Academy, or Zero-Point Security, all of which have their own strengths. For me, however, OffSec’s emphasis on hands-on learning, realistic enterprise scenarios, and understanding the underlying techniques makes it my preferred training provider.

OffSec also describes OSEP as a certification that bridges advanced penetration testing and realistic red team operations:

Red Teaming vs Penetration Testing

Before moving on to the syllabus, it’s worth understanding where PEN-300 fits within the broader OffSec training path. Following the 200-level (foundational) courses, OffSec offers three advanced 300-level courses: PEN-300 (Evasion Techniques and Breaching Defenses), WEB-300 (Advanced Web Attacks and Exploitation), and EXP-300 (Windows User Mode Exploit Development). These courses lead to the OSEP, OSWE, and OSED certifications respectively. Successfully earning all three certifications automatically awards the OSCE³ (OffSec Certified Expert 3) certification.

Who Should Take PEN-300?

I would recommend PEN-300 to anyone who:

• Has already completed the OSCP or has equivalent hands-on penetration testing experience.
• Wants to develop advanced offensive security skills.
• Wants to learn how to operate effectively in enterprise environments while adapting to common defensive controls.
• Wants to bridge the gap between advanced penetration testing and realistic red team operations.

If you’re completely new to penetration testing, I would recommend starting with PEN-200 before tackling PEN-300.

Don’t underestimate PEN-300. Although it naturally builds on OSCP, the course introduces considerably more advanced concepts and expects you to understand and adapt offensive techniques rather than simply relying on publicly available tools. Make sure you’re comfortable with the fundamentals covered in OSCP before starting.

Syllabus

My recommendation is to purchase the Learn One subscription if possible. The additional time allows you to work through every chapter, complete every lab, and truly understand the material instead of rushing towards the exam.

The official syllabus is available here:

Official PEN-300 Syllabus

The PEN-300 course material is delivered through OffSec’s web-based learning platform. I found the interface intuitive and easy to navigate, and it allows OffSec to keep the course content up to date. If you prefer studying offline, you can also request and download the complete course material as a PDF.

Take your own notes while progressing through the course. Save useful commands, code snippets, and payloads. Once you’ve completed the modules, move on to the challenge labs.

One of PEN-300’s biggest strengths is that it encourages you to understand the underlying techniques rather than simply relying on existing tools. When I started the course, I had only a basic understanding of Active Directory and payload development. By the end, I felt far more comfortable developing and adapting my own payloads while understanding why the underlying techniques work.

Challenge Labs

The course contains eight challenge labs with increasing difficulty. Rather than attacking isolated hosts, you’ll work inside interconnected Active Directory environments that encourage proper enumeration, lateral movement, and privilege escalation.

My recommendation is to complete the challenge labs in order from one through eight before attempting the exam.

Exam

Without giving away any spoilers, I genuinely enjoyed the exam. The objectives felt realistic and rewarded understanding rather than memorisation. There are multiple ways to obtain a passing score, allowing you to adapt your approach.

Official Exam Guide:

OSEP Exam Guide

My Preparation

My preparation was straightforward:

1. Complete every course module.
2. Finish every accompanying lab.
3. Take detailed personal notes.
4. Save useful commands, code snippets, and payloads.
5. Complete all challenge labs in order.
6. Document every attack path.

Having organised notes made revision much easier.

Recommendation

My recommendation: Don’t rush through the course. Complete every module, finish every lab, take detailed notes, and work through all eight challenge labs before attempting the exam. You’ll get much more value from the course than if you simply study to pass the certification.

Was PEN-300 Worth It?

Absolutely. I enjoyed every bit of it and would happily recommend it to anyone looking to move beyond traditional penetration testing.

Conclusion

Looking back, I’m really glad I decided to take PEN-300. It was challenging, but it was also one of the most enjoyable courses I’ve completed.

The biggest takeaway for me wasn’t learning another tool or technique. It was learning how to think differently during an engagement, understand why techniques work, and adapt them when things don’t go as planned.

If you’re willing to invest the time, complete the labs, and make the most of the course material, I believe PEN-300 is absolutely worth it.

Final Thoughts

Compared to the OSCP, PEN-300 goes significantly deeper into advanced offensive techniques, payload development, and operating within enterprise environments. While OSCP teaches you how to compromise systems, PEN-300 teaches you how to operate effectively once you’ve gained access.

For me, this was one of the most enjoyable and practical offensive security courses I’ve completed. Much of what I learned can be applied directly during real-world engagements, making it one of the most valuable certifications I’ve earned so far.

Additional Resources

During my preparation, I came across many excellent blogs, cheat sheets, and reference websites. Below are some of the resources that I personally found the most helpful throughout my PEN-300 journey.

• LOLAD Project
• OSEP Notes - Emmanuel Solis
• Steffin Stanly OSEP Notes
• Command Manager
• OSEP Playground
• IppSec
• 0xdf
• Reverse Shells
• HackTricks Active Directory
• Pentest Cheat Sheet
• NetExec Wiki

Certificate

Thanks for taking the time to read my review. I hope it has given you a better idea of what to expect from PEN-300 and whether it’s the right next step in your offensive security journey.

You can verify my OSEP certification by clicking on the certificate below.