Description
The system administrator of your company needs your expertise in cryptography.
The confidentiality of several files has been compromised, which indicates that an attacker has broken RSA-2048 on this machine.
A preliminary analysis conducted by one of your intern shows that the only process of interest running during the attack was /usr/local/bin/python3.8.
IoCs reveal a potential backdoor.
We provide you this binary as well as a remote access to the Python prompt.
There is no need to look outside the Python prompt for this challenge, nor even trying to escape it.
You are also given access to a signature oracle accessed by the attacker running on the compromised machine (oracle.py).
Your goal is to understand how the attacker proceeded, to factor the keys generated and ultimately to decrypt the content of the file being sent to you.
Services:
- Python :
nc localhost 4001 - Signature :
nc localhost 4000
Note : the challenge Bugs Buggy from FCSC 2020 has been split into two challenges for Hackropole. A simpler variant is available here: Bugs Buggy Easy.
Files
- docker-compose.yml
-
python3.8
16.46 MiB – b8f33291abc56422e0bd40becd2a54a7780f42eb7ac3523d6ec06cec63dcc00f -
oracle.py
805 B – 49b9ad4c12f72cd9641ef2484c4e4a63a67d02f27b07e9f58b932d643ac00772
Author
Challenge Instructions
- First, download docker-compose.yml:
curl https://hackropole.fr/challenges/fcsc2020-crypto-bugs-buggy/docker-compose.public.yml -o docker-compose.yml - Launch the challenge by executing in the same folder:
docker compose up - Then, in another console, access the challenge with Netcat:
nc localhost 4001 - Then, in another console, access the challenge with Netcat:
nc localhost 4000
In case you encounter problems, please consult the FAQ.
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