Free Services

Platform: HackTheBox | Category: Forensics | Difficulty: Easy | Author: D3v0o0Nu11 | Date: 2026-02-10

Description

Intergalactic Federation stated that it managed to prevent a large-scale phishing campaign that targeted all space personnel across the galaxy. The enemy's goal was to add as many spaceships to their space-botnet as possible so they can conduct distributed destruction of intergalactic services (DDOIS) using their fleet. Since such a campaign can be easily detected and prevented, malicious actors have changed their tactics. As stated by officials, a new spear phishing campaign is underway aiming high value targets. Now Klaus asks your opinion about a mail it received from "sales@unlockyourmind.gal", claiming that in their galaxy it is possible to recover it's memory back by following the steps contained in the attached file.

Solution Approach

Core idea: Identify the weakness from source review or fingerprinting first. Iterate with incremental payloads instead of guessing.

Steps

1. First, unzip the .zip file given.

2. Well we can't view this file in kali linux, let's open it in windows.

3. At the other sheet, we got this:

4. Based from the macro formula we got at Macro1, we know that all the integer values in column E, F, and G are XORed with 24.

5. The logics of XOR, if we XOR it again, the original value shall returned.

6. First saved the macro sheet as free_decryption.csv.

Flag

(no flag captured)

Lessons Learned

1. Identify the weakness from source review or fingerprinting first.
2. Iterate with incremental payloads instead of guessing.
3. Reuse the same pattern in future engagements.