The Corydon blog.

CompTIA A+

CompTIA A+ Study Plan From a Best-Seller Author — How to Pass in 8 Weeks

Eight weeks, ten hours a week, and a schedule built around how the exam is actually weighted.

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CompTIA A+

The 12 Ports Every A+ Candidate Fails On (And How to Never Forget Them!)

Cut the list to what appears, learn them in pairs, verify them in your own terminal.

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CompTIA A+

A+ Core 1 vs Core 2: What Actually Changes Between the Two Exams

Two exams, one certificate, completely different skills and study habits.

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CompTIA A+

Performance-Based Questions Explained: Why Most A+ Candidates Lose Here?!

They are weighted heavily, they eat your clock, and they punish memorisation.

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CompTIA A+

I Fixed 700 Laptops in My Whole Career. Here Are the 7 Faults That Cover Half the A+ Exam

Real repair work clusters around a handful of failures that map onto the exam.

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PenTest+

The Client Said "You'll Never Get In." We Were Domain Admin by Lunch.

A flat network and one weak service account. A real engagement, mapped to PT0-003.

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Web Security

SQL Injection Is Still #3. Here's Exactly How It Still Happens

The exact code that causes it, the one line that fixes it, and why it refuses to die.

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Cloud & AWS

The IAM Policy Mistake That Opens Your Whole AWS Account

Two characters separate a locked-down account from one an attacker owns.

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Kubernetes

Kubernetes for People Who Keep Bluffing in Standups

The honest, jargon-free mental model that makes the whole thing click.

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AI & AgentOps

AI Agents in Production: Why Most Demos Never Survive Real Users

The gap between an agent that dazzles in a demo and one that survives real users — and the engineering that closes it.

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LLM Engineering

LLM Engineering: Cutting Token Costs 60% Without Losing Quality

Most LLM bills are bloated by habit, not necessity. The levers that cut cost without cutting quality.

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AI & Data

RAG Explained With Real Code (And When You Shouldn't Use It)

How retrieval-augmented generation works, the whole thing in code, and when to skip it.

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PenTest+

I Failed PenTest+ the First Time. Here's the Domain That Killed Me.

I could pop a shell in my sleep and still failed PT0-003. The domain I dismissed as paperwork.

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PenTest+

How a Forgotten Office Printer Gave Us the Entire Network

Nobody patches the printer or changes its password. On engagement after engagement, it is the first domino.

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PenTest+

The Password Spray That Took 4 Minutes and Opened 200 Accounts

No brute force, no alarms. One common password tried against every user at once.

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PenTest+

Nobody Fails PenTest+ on the Hacking. They Fail on the Paperwork.

Candidates fear the technical questions and fail on scoping, rules of engagement, and reporting.

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PenTest+

The 3 Words in a Rules-of-Engagement Doc That Can End Your Career

"And associated systems." Three innocent words that have turned authorised tests into legal cases.

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PenTest+

We Found the Vulnerability in 20 Minutes. The Report Took 3 Days.

Breaking in is fast and invisible. The report is slow and the only thing the client ever sees.

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PenTest+

Why Your Metasploit Habit Will Cost You Marks on PT0-003

Frameworks make you fast and lazy. The exam tests the understanding a one-click habit erodes.

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PenTest+

Post-Exploitation: What Real Attackers Do After They're Already In

The first shell is the beginning, not the end. Persistence, escalation, lateral movement, exfiltration.

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PenTest+

I Read 50 Pentest Reports. The Good Ones All Did This One Thing.

The difference between reports that drove change and reports that gathered dust was one habit.

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PenTest+

The Wi-Fi Attack That Somehow Still Works in 2026

Evil-twin and handshake-capture attacks from a decade ago still hand over credentials today.

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PenTest+

Social Engineering: The Domain You Cannot Practise in a Lab

You can rebuild a network attack a hundred times. You cannot rebuild a human being.

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PenTest+

The Scan That Took Down Production — And What We Should Have Done

An aggressive scan against a fragile legacy system took production offline mid-business-day.

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PenTest+

From Helpdesk to Red Team: The Path Nobody Tells You About

The most reliable route to a red-team seat runs through the helpdesk, the SOC, and the systems you first learned to fix.

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