HackTheBox Baby RE Writeup

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

https://app.hackthebox.com/challenges/92

Description

Show us your basic skills! (P.S. There are 4 ways to solve this, are you willing to try them all?)

Exploitation

To retrieve the flag, you can choose one of the following methods:

• Decompile the binary and analyze the main function.
• Use ltrace to determine the correct strcmp value and run the program with the expected input.
• Execute the following command to extract and reconstruct the flag directly:

objdump -D baby | grep -E "movabs.*0x|movl.*0x|movw.*0x" | grep -oE "0x[[:alnum:]]{4,16}" | while read -r line; do
  printf "%s" "${line:2}" | xxd -r -p | rev 2>/dev/null
done

Summary

The Baby RE Challenge on Hack The Box is an easy-level reverse engineering puzzle that introduces basic binary analysis and decompilation techniques. Participants can retrieve the flag by either decompiling the binary to analyze the main function or using command-line tools like objdump and xxd to extract and decode embedded data. Ideal for beginners, this challenge provides hands-on experience with reverse engineering and binary forensics, offering a practical introduction to decompilation, data extraction, and basic scripting. It encourages exploring multiple solutions, making it a versatile learning opportunity for newcomers to cybersecurity.