The Web3 Security Auditor’s Handbook : Mastering Smart Contract Hacking, DeFi Protocols, and Solidity Vulnerabilities

Smart contracts don’t “get hacked.”

They get shipped with bugs… and discovered the expensive way.

Welcome to The Web3 Security Auditor’s Handbook — a practical, no-fluff guide to auditing smart contracts like an attacker, and writing reports like a professional.

If you’ve ever opened a DeFi repo and thought:

“Nice code. Which function loses $20M?”

You’re in the right place.

I’m Julian Sloane, and I wrote this book for people who want real Web3 security skills — not theory, not vibes, not copy-pasted checklist memes.

This is the handbook for learning how exploits happen in the real world, and how to catch them before they become a post-mortem thread.

In this book, you’ll learn how to:
Read smart contract code like an auditor (fast, systematic, and ruthless) Map a protocol’s attack surface in hours, not weeks
Spot and exploit the most common Solidity vulnerabilities

(reentrancy, access control failures, unsafe external calls, signature bugs, DoS patterns, and more)

Break protocol assumptions using “weird” tokens

(fee-on-transfer, rebasing, ERC777 hooks, non-standard ERC20 behavior)

Audit DeFi’s #1 danger zone: accounting math

(shares, debt, interest indexes, rounding, decimals, precision loss)

Understand how AMMs, lending markets, vaults, and reward systems fail

Identify oracle weaknesses, price manipulation setups, and flash-loan exploit paths

Review upgradeability and governance like you assume the admin key is cursed (because it is)

Use fuzzing + invariants to catch bugs humans miss

Write clean PoCs and audit findings that dev teams can actually reproduce and fix

What makes this different from other Web3 security books?

Most resources explain bugs.

This book teaches you how auditors prove them.

You’ll build:
Practical exploit PoCs Mainnet-fork test setups “evil token” test cases to stress protocols DeFi accounting invariants you can reuse everywhere Auditor-ready report templates and retest checklists A full end-to-end audit case study you can learn from (or use for your portfolio)
Who this is for
Aspiring smart contract auditors Web3 developers who want to stop shipping “funds are safu” Bug bounty hunters leveling up into DeFi exploit workflows Security engineers who want DeFi knowledge without the nonsense
If you want a book that’s practical, entertaining, and built for real audits — this is it.

Let’s break DeFi.

So you can fix it.