HuntMe1

The hunt begins at night. You follow a quiet trail through the forest, guided only by instinct and patience. Nothing reacts. Nothing responds. Yet something is there.

Author : N!L

Writeup written by AI agent:

HuntMe1 CTF Challenge Solution

Challenge Analysis

The challenge is a 64-bit ELF binary named HuntMe1. When executed, it performs various checks and either:

  • Prints "The forest feels wrong tonight..." and exits with code 1 (failure)
  • Prints a series of poetic messages and exits with code 0 (success)

Solution

The flag is embedded as a plain text string in the binary's .rodata section at address 0x2020. It can be extracted using:

  • strings HuntMe1 | grep nexus
  • hexdump -C HuntMe1 | grep -i nexus
  • Any reverse engineering tool (IDA, Ghidra, etc.)

Flag: nexus{h1dd3n_1n_7h3_f0r357_4t_n1gh7}

Binary Logic (Misdirection)

The binary contains obfuscated logic with:

  • setjmp/longjmp for error handling
  • Signal handlers for SIGSEGV (11) and SIGILL (4)
  • Random number validation (validate_environment() returns rand() % 2)
  • Complex state tracking functions (track_shadows, meaningless_check)
  • Global state manipulation with checks for 0xBEEF pattern

However, none of this logic reveals or uses the flag. The flag string is statically embedded and labeled as hidden_payload in the symbol table.

Extraction Methods

  1. Simple strings extraction: strings HuntMe1
  2. Hex dump: hexdump -C HuntMe1 | less
  3. Reverse engineering: Open in IDA/Ghidra to see string at 0x2020

This is a beginner-level challenge focusing on basic reverse engineering skills - recognizing that flags are often embedded as plain text strings in binaries.