###### We intercepted Sophia new defense system. It seems like she is using some kind of filter in the command sent to a certain server. There is also another security measure that we could not identify, we need a bypass.

TL;DR. This print contains the entire solve


It was given to us the dockerfile and some Elixir/Erlang files. So instinctively we build the docker with
```
docker build .
```

After we started our docker with
```
docker run image_id
```

We can see the following message:

> Inserting 'Elixir.KillMe.Server', get_flag into blacklist

Then we connect to the docker, or the official server, with netcat or similar
```
nc ip 4000
```

And ask for the key that was previously blacklisted
```
Elixir.KillMe.Server.get_flag
```
I don't know if it was the intended way but this print us the flag
> CTF-BR{4f7er_7wEn7y_YE4r5_Erl4N9_57ill_D0_N07_H4VE_4_54nD80X}