TryHackme’s Advent of Cyber 2023 — Day 16 Writeup

Machine learning Can’t CAPTCHA this Machine!

Learning Objectives

- Complex neural network structures

- How does a convolutional neural networks function?

- Using neural networks for optical character recognition

- Integrating neural networks into red team tooling

Convolutional Neural Networks

In the previous tasks, we talked about neural network structures. However, most of these structures were fairly basic in nature. Today, we will cover an interesting structure called a convolutional neural network (CNN).

CNNs are incredible ML structures that have the ability to extract features that can be used to train a neural network. In the previous task, we used the garbage-in, garbage-out principle to explain the importance of our inputs having good features. This ensures that the output from the neural network is accurate. But what if we could actually have the neural network select the important features itself? This is where CNN comes into play!

In essence, CNNs are normal neural networks that simply have the feature-extraction process as part of the network itself. This time, we’re not just using maths but combining it with…