📔
CTF Writeups
RedTeam Capstone Challegen TryHackMeTryHackMeHackTheBox
  • Hello
  • Red Team Capstone Challenge TryHackMe
    • OSINT
    • Permieter Breach
    • Initial Compromise of Active Directory
    • Full Compromise of CORP Domain
    • Full Compromise of Parent Domain
    • Full Compromise of BANK Domain
    • Compromise of SWIFT and Payment Transfer
  • Try Hack Me
    • 2025
      • Robots
      • Billing
      • Crypto Failures
      • Smol
      • Silver Platter
      • The Sticker Shop
      • Lo-Fi
      • Light
      • Lookup
    • 2024
      • Breakme
      • New York Flankees
      • Publisher
      • Capture Returns
      • mKingdom
      • Creative
      • Clocky
      • Hack Smarter Security
      • Kitty
      • Breaking RSA
      • Umbrella
      • SSRF
      • Capture!
      • WhyHackMe
      • Stealth
    • 2023
      • AVenger
      • Slingshot
    • Advent of Cyber 2023
      • Day 1
      • Day 2
      • Day 3
      • Day 4
      • Day 5
      • Day 6
      • Day 7
      • Day 8
      • Day 9
      • Day 10
      • Day 11
      • Day 12
      • Day 13
      • Day 14
      • Day 15
      • Day 16
      • Day 17
      • Day 18
      • Day 19
      • Day 20
      • Day 21
      • Day 22
      • Day 23
      • Day 24
  • Hack The Box
    • 2024
      • Jab
      • IClean
      • Skyfall
      • Headless
      • Blue
Powered by GitBook
On this page

Was this helpful?

  1. Try Hack Me
  2. Advent of Cyber 2023

Day 16

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

This room is again a very straightforward one with all commands and instructions already given. We just need to follow along and run them.

What key process of training a neural network is taken care of by using a CNN? Submit
[REDACTED]

This can be found in the reading section at the begining
What is the name of the process used in the CNN to extract the features?
[REDACTED]

This can be found in the reading section at the begining
What is the name of the process used to reduce the features down?
[REDACTED]

This can be found in the reading section at the begining
What off-the-shelf CNN did we use to train a CAPTCHA-cracking OCR model?
[REDACTED]

This can be found in the reading section at the begining
What is the password that McGreedy set on the HQ Admin portal?
[REDACTED]

This can be found once the CNN model has been exported and hosted. We then run the bruteforce.py program given.
cd ~/Desktop/bruteforcer && python3 bruteforce.py
[-] Prediction probability too low, not submitting CAPTCHA
[-] Invalid credential pair -- Username: admin Password: Spring2017
[-] Incorrect CAPTCHA value was supplied, we will resubmit this password
[-] Invalid credential pair -- Username: admin Password: Spring2021
.
.
.
[-] Invalid credential pair -- Username: admin Password: sysadmin
[-] Invalid credential pair -- Username: admin Password: water
[-] Invalid credential pair -- Username: admin Password: dirt
[-] Invalid credential pair -- Username: admin Password: air
[-] Invalid credential pair -- Username: admin Password: earth
[+] Access Granted!! -- Username: [REDACTED] Password: [REDACTED]
What is the value of the flag that you receive when you successfully authenticate to the HQ Admin portal?
[REDACTED]

With the username and password found we just need to enter it into the site along with the CAPTCHA. This will give us the flag.

PreviousDay 15NextDay 17

Last updated 1 year ago

Was this helpful?