CJCA is a genuinely strong entry-level cert. The hands-on exam pairs a pentest with investigating a similar attack chain in the SIEM, which is a rare “purple team” structure I wish existed when I started out. It’s worth taking on the way to CPTS or CDSA if you’re early-career; if you’re mid-career, it’s not going to move the needle on its own, but the material and exam still hold up as solid practice.

Why I took CJCA

Hack The Box (HTB) markets the CJCA as an entry-level stepping stone toward advanced Certs like HTB Certified Penetration Testing Specialist (HTB CPTS) or HTB Certified Defensive Security Analyst (HTB CDSA). On its own, a certificate with “junior” in the title won’t dazzle HR or secure mid-level roles, but it makes sense to complete on the way to more advanced Certs as a free CJCA voucher is included with an annual HTB Academy subscription. The CJCA path completes 30% of the CDSA path and 10% of the CPTS path; the core modules of CJCA overlap with the more advanced Certs.

HTB is an awesome platform I did piles of their boxes while preparing for the OSCP. At the beginning of my career, about a decade ago, I yearned for a “HTB for Blue Team” - a turnkey platform where you could launch lab environments at the click of a button. The CJCA is the exact foundational course I wish I had back then.

It strongly covers core concepts, encourages independent research, and provides hands-on practice. The exam gives you a clear target to aim for: you perform a small penetration test, investigate resulting security alerts, and write a professional report covering both. Because you attack and defend the exact same network, you get a full “purple team” perspective on how offensive actions generate log evidence.

While the material can feel daunting for a beginner, the CJCA sets you up to succeed. You get a generous 5-day exam window, free retakes, and actionable feedback if you don’t pass on your first attempt.

The Fundamentals

There are a ton of fundamentals to cover, course lists the total content time as around 411 Hours and it can take significantly longer if you take the suggested practice and reading materials seriously. The coverage of related basics is thorough. While some of it requires independent effort—like actually setting up backups, SELinux, AppArmor, TCP Wrappers, or ICACLS to understand how they work—it’s a powerful way to learn. That said, many of these are treated as “exercises left to the reader”, that you can easily skip. I have mixed feelings about this. Depending on your experience level, building a small web app with a backend database just to practice SQL injection on your own can be daunting and potentially discouraging when you find yourself stuck on a “problem zero” before even getting to what you intended to study. However, this can be very rewarding if you work through it. Early in my career the Air Force put me through training and I made a point to write down every tool mentioned and install it on my own to play with. Taking on “exercise left to the reader” prompts with sheer enthusiasm and ignorance built a strong practical foundation for me.

Throughout the course, I kept waffling between “I wish every junior knew this” and feeling like the overall structure lacked coherence. Without enough context, a beginner might find it overwhelming. For instance, the Windows CLI module uses examples focused on privilege escalation and persistence, but a newbie will only see registry changes or file queries without understanding why those actions matter.

The sheer volume of material is a beast. You’ll be over 50% through the course before touching penetration testing, and 84% through before hitting the defensive modules—the final five modules are blue team focused. While it might frustrate someone eager to “learn hacking,” starting with the basics is the right call. Without understanding system administration, networking, and code, you aren’t really learning how to hack—you’re just memorizing attack paths you don’t understand.

Because the modules don’t strictly build on each other and are designed to be taken piecemeal, expect some repeated definitions and concepts.

The course shines brightest during the interactive labs, but beginners still need to eat their vegetables and digest the non-hands-on sections. The referenced links are gold. Learning how to read documentation is a critical skill in security; I still have fond memories of reading through the Nmap manual early in my career to understand not just what flags did, but how they worked under the hood.

Red and Blue Sections

The second half of the course is where the material truly shines. Even modules like “Using the Metasploit Framework” felt engaging because the examples demonstrated full box compromises rather than isolated commands.

Honorable mentions for Modules:

• Intro to Web Applications
• Pentest in a Nutshell
• Footprinting
• Hacking Wordpress
• Windows Event Logs & Finding Evil
• Security Monitoring & SIEM fundamentals

If you’re just starting out on Hack The Box, TryHackMe, or VulnHub, I’d strongly recommend “Pentest in a Nutshell” and “Footprinting”. Beginners often struggle to build a cohesive methodology while learning individual hacking techniques; Pentest in a Nutshell delivers that overarching methodology efficiently, while Footprinting provides a fast-paced walkthrough of the common services you’ll encounter.

Though I learned about it too late to use it myself, I also recommend completing the 10-box CJCA Prep Track. It’s great test preparation if you haven’t already worked through some of HTB’s Easy boxes.

The defensive modules feel a bit disjointed. During the practical labs, it isn’t always clear how you would reach a solution using only the course material. However, that aligns with the reality of the field: if you can only perform tasks you were explicitly trained on, you’re waiting to be replaced by a script, an automated tool, or an AI agent.

The “Windows Event Logs & Finding Evil” module perfectly illustrates this need to look beyond the provided text. If you aren’t familiar with a specific attack or how to detect it, you have to do independent research. While I enjoyed the concepts, the module eventually shifts into using PowerShell commands to parse specific event logs based on provided hints. While that offers great Powershell practice and familiarizes you with Windows Logs, it doesn’t reflect real-world threat hunting—where you rely on a SIEM, EDR, or specialized tools like Hayabusa—nor does it reflect the CJCA exam itself, where a SIEM is provided.

Finally, Intro to SOC/SIEM requires you to make subjective judgment calls during the Skill Assessment. Incorporating analyst judgment is the right approach for realistic training, though it can occasionally feel frustrating on a gamified platform if your reasoning doesn’t align with the author’s key.

Exam

The course itself doesn’t provide much context on report writing, but reddit and blogs stress the importance of the report and recommend SysReptor. For the Pentest portion of the CJCA reporting primarily centers on proof-of-concept (PoC) walkthroughs that enable someone to clearly reproduce your attack steps. For the SIEM Assessment portion of the CJCA reporting you fill in a spreadsheet of alerts, labeling them as true/false positive and provide evidence (reasoning).

There is a Reporting Module referenced during the course, I took that module and while it serves as a solid introduction to professional documentation, it may be overkill for the test, and the hands on portion of the documentation module is an Active Directory Pentest which is out of scope for the CJCA. Just like the rest of the course, I’d recommend overlearning the content and making opportunities to practice. Writing is a skill of vital importance and time spent honing that skill isn’t wasted.

Pentest Strategy

For the offensive portion, I maintained full tmux CLI logging and took screenshots for any GUI actions. Whenever I achieved a milestone—such as initial scans, Remote Code Execution (RCE), or privilege escalation—I saved the terminal session and screenshots with a descriptive name that includes the target machine’s name.

Rather than waiting until the end, I drafted the technical walkthrough (PoC) with tmux logs, screenshots, and brief explanations right after completing each box. Doing this while the details were fresh made it easy to grab necessary artifacts like hashes, screenshots, and evidence. Once every box was done, I polished the report as a whole to ensure consistency and completeness.

If you’re looking to refine or build your own tmux workflow I’d recommend these resources:

• Daniel Miessler’s Tmux Guide
• IppSec’s Intro to Tmux

I used SysReptor with the CJCA template to write my report. I strongly suggest testing SysReptor ahead of time rather than trying to figure it out on exam day. I wrote a sample report for a single HTB Easy box prior to the test to get used to the interface, though I still found myself occasionally missing features found in standard document editors(e.g. Google Workspace, Office, or Markdown/LaTeX).

Blue Team Strategy

For the defensive portion, you are tasked with reviewing listed alerts in a spreadsheet, triaging them as True or False Positives, and providing supporting evidence. I initially overthought this section; the instructions are vague regarding what constitutes “evidence.” Given that it’s submitted via a spreadsheet, aim for concise 2-3 sentence explanations rather than dumping raw log files, hashes, screenshots, or Elastic queries. I found it easier to first write longer explanations with what I had found as well as links to elastic queries then cut the explanation down so it would be legible in a table on the report.

Exam Takeaways

• Look at the big picture. Don’t assume the pentest environment consists of isolated targets. I spent unnecessary energy stressing over the final targets before realizing they were connected and post exploitation on the previous box would help me move forward. It’s an interconnected environment, not five standalone HTB boxes. The Blue Team section is related as well. My attack path differed a little bit from the one detected during the SIEM assessment, but these sections can certainly inform each other.
• Don’t Underestimate the Exam: Although I hold an OSCP and work in Security Engineering, I took this exam seriously. This is an excellent opportunity to practice your skills. The course material is sufficient if you deeply understand the underlying concepts. For the pentest portion, the course material sets you up to hone your methodology, but not to do specific attacks needed on the test. Practice what you learn on live targets (e.g., solving HTB Easy boxes) to lock in your methodology. Expect a little bit of figuring it out unless you already have an arsenal of attacks you understand.
• The defensive modules don’t fully prepare you for the exam’s practical demands. Find opportunities to practice alert triage in Elastic on your own—focus on querying, filtering out noise, and pivoting between related events (e.g., tracking child processes or correlated network events).

Who Should Take CJCA?

If you’re early in your career, this certification offers a strong, practical foundation and prepares you for other Certs like OSCP, CDSA, or CPTS. If you’re mid-career, no individual cert will make or break your trajectory. The real value is in being the kind of practitioner who seeks to continue learning and training. I might not know exactly which skill set I’ll rely on next year, but keeping the fundamentals sharp and building daily learning habits is an investment that never goes to waste.