HackTheBox Computational Recruting Writeup

Explore the basics of cybersecurity in the Computational Recruting Challenge on Hack The Box. This very-easy-level Challenge introduces encryption reversal and file handling concepts in a clear and accessible way, perfect for beginners.

import re
from pwn import *

def get_process():
    try:
        host, port = sys.argv[1].split(':')
        return remote(host, int(port))
    except IndexError:
        print(f'Usage: python {sys.argv[0]} <ip:port>')
        exit(1)

def get_candidates(file_path):
    pattern = r"^\s*([A-Za-z]+)\s+([A-Za-z]+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s*$"
    candidates = []
    with open(file_path, 'r') as f:
        for line in f.readlines():
            match = re.search(pattern, line.strip())
            if match:
                candidates.append(match.groups())
    return candidates

def calculate_values(candidates):
    weights = {'Health': 0.18, 'Agility': 0.20, 'Charisma': 0.21, 'Knowledge': 0.08, 'Energy': 0.17, 'Resourcefulness': 0.16}
    data = []
    for candidate in candidates:
        first_name, last_name, health, agility, charisma, knowledge, energy, resourcefulness = candidate
        skill_scores = {
            'Health': round(6 * (int(health) * 0.2)) + 10,
            'Agility': round(6 * (int(agility) * 0.3)) + 10,
            'Charisma': round(6 * (int(charisma) * 0.1)) + 10,
            'Knowledge': round(6 * (int(knowledge) * 0.05)) + 10,
            'Energy': round(6 * (int(energy) * 0.05)) + 10,
            'Resourcefulness': round(6 * (int(resourcefulness) * 0.3)) + 10
        }
        overall_value = round(5 * (skill_scores['Health'] * weights['Health'] +
                                   skill_scores['Agility'] * weights['Agility'] +
                                   skill_scores['Charisma'] * weights['Charisma'] +
                                   skill_scores['Knowledge'] * weights['Knowledge'] +
                                   skill_scores['Energy'] * weights['Energy'] +
                                   skill_scores['Resourcefulness'] * weights['Resourcefulness']))
        data.append((f"{first_name} {last_name}", overall_value))
    return data

def sort_candidates(data):
    return sorted(data, key=lambda x: x[1], reverse=True)[:14]

def get_flag(sorted_candidates):
    io = get_process()
    solution = ', '.join(f"{name} - {score}" for name, score in sorted_candidates)
    io.recvuntil(b'> ')
    io.sendline(solution.encode())
    flag = io.recvall().decode().strip()
    return flag

if __name__ == '__main__':
    file_path = 'data.txt'
    candidates = get_candidates(file_path)
    calculated_values = calculate_values(candidates)
    sorted_candidates = sort_candidates(calculated_values)
    flag = get_flag(sorted_candidates)
    print(flag)

Summary

The Computational Recruiting Challenge on Hack The Box is an easy-level challenge where you parse candidate data, calculate skill scores based on predefined weights, and sort candidates. The script sends the top 14 candidates to a remote service, which returns the flag. It’s perfect for beginners to practice data parsing and calculation.