Steel Sentry

reverse linux x86/x64 FCSC 2026 solved on

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Description

The Sentinelle company has developed a revolutionary license control system with wave-based presence verification. You are invited to test this new product, Steel Sentry, in order to verify its robustness before purchasing it.

Normally, this product is supplied with a hardware component connected to the PC to ensure foolproof protection. In your case, and because Sentinelle does not want an overly intrusive security evaluation, you will only be given a test software version. To make things even more difficult, the company has configured its license server so that, even if you were to get hold of such a dongle, you still would not be able to pass the verification.

Will you still manage to find the license?

Files

Author

pva

Challenge Instructions

  1. First, download docker-compose.yml:
    curl https://hackropole.fr/challenges/fcsc2026-reverse-steel-sentry/docker-compose.public.yml -o docker-compose.yml
  2. Launch the challenge by executing in the same folder:
    docker compose up
  3. Then, in another console, access the challenge with Netcat:
    nc localhost 4000
⚠️ Important: You must solve the challenge by interacting with the Docker container through the exposed network port. Any other way is not considered valid.

In case you encounter problems, please consult the FAQ.

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