Knowing how intrusions happen is only useful if it changes what you build. The good news is that defence doesn't require matching an attacker technique for technique. It requires making the chain expensive to complete. These are the controls that reliably earn their cost, roughly in order of return. 1. Know what you're running You cannot defend an asset you've forgotten. An accurate inventory of internet-facing services, domains, and cloud resources is unglamorous and consist

Protocols spend heavily auditing their smart contracts and comparatively little on everything around them. It's an understandable instinct — the contract holds the funds. But an audited contract sitting behind an unaudited stack is a strong front door on a building with the windows open. The gap exists for a structural reason. Traditional security firms usually don't read Solidity, and contract auditors usually stop at the contract boundary. Very little assessment covers the

Most breaches don't look like the films. There's rarely a single dramatic exploit. There's a chain of small, individually unremarkable weaknesses, and someone patient enough to link them together. Understanding that chain is what separates a security programme that works from a pile of tools that doesn't. Here's how the work actually goes. 1. Reconnaissance: mapping what you forgot you had Before anything is attacked, it's inventoried. An attacker enumerates subdomains, check

Most people who try to learn cybersecurity quit in the first month. Not because it's hard, but because they start by collecting — a bookmarks folder of tools, six half-watched playlists, a Kali VM opened twice. Collecting feels like progress. It isn't. Every lesson here ends with something you can run in the next ten minutes. That's the whole method: read a little, do it immediately, move on. Start with these three 1. Linux for Security Work — the filesystem, permissions, and

Smart contracts are unusual software. The code is public, the money is inside it, anyone can call it, and you often cannot patch it. Attackers get unlimited attempts against a target that cannot move. So the vulnerability classes are narrow and well documented, and protocols keep losing money to them. Below, you'll build a vulnerable vault and drain it yourself. 1. Reentrancy When a contract makes an external call, it hands control to that address. If the recipient is a contr

You don't need to be a Linux administrator to work in security. You do need to stop being slowed down by the shell, because everything else assumes you aren't. Open a terminal now and run these as you read. It takes about fifteen minutes and it'll stick far better than reading alone. The filesystem is one tree No drive letters. Everything hangs off /. Have a look: $ ls / bin boot dev etc home lib media mnt opt proc root run sbin srv tmp usr var The ones that m

Security work is mostly reasoning about things you can't see directly. Networking is where that starts — you can't assess a system without a mental model of how its traffic moves. Everything below runs with tools already on your machine. Follow along. Addresses and ports An IP address identifies a machine. A port identifies a service on it. Together they're an endpoint: 93.184.216.34:443 means the HTTPS service on that host. See what's listening on yours: $ ss -tulpn Netid St