MC 7 (Dynamic Analysis)

Platform: rev-kids20.forkbomb.ru | Category: Reversing | Type: Challenge | Difficulty: Easy | OS: NA | Author: XESXOR | Date: 2026-03-09 | Status: Solved Techniques: arithmetic_trace, disassembly_analysis

Summary

Language: C. Binary only. "Guess the number once again! App won't keep it in a variable this time."

MC 7 (Dynamic Analysis) — Reverse Kids 2.0

Description

Language: C. Binary only. "Guess the number once again! App won't keep it in a variable this time."

ELF 64-bit, dynamically linked, not stripped.

Analysis

The number is not stored in a variable directly — it is computed from several arithmetic operations. Through disassembly, we trace the calculations.

Solution

Tracing the arithmetic operations in the disassembled code yields the final value REDACTED. ‍​‌‌​​‌​​​‌‌​​‌​​​​‌‌​‌​​​​‌‌‌​​‌​​‌‌​​​‌​​‌‌‌​​​​​‌‌​‌‌​​​‌‌​​​​‍