After downloading file we can see that it's x86 ELF. The description tells us nothing, so the best way to understand what is it --- execution:) When we execute it, we will see a newly created conlose with very-very fast changing pictures (every picture is a set of ASCII symbols). Hmm.. maybe something intresting is hidden in those pictures?.. Let's take a look!
First we see the text on the page: "You must specify a nick". After quick look into source code of the page we understand that our URL must contain GET-parameter 'nick' with random value.
Then server sends us some leet-modified string like
51xty tw0 plu5 0n3
and expecting from us solution of this expression in the same format.
Experimentally found that there is only 4 leet-modified characters: '1' == 'i', '3' == 'e', '5' == 's', '0' == 'o'.
The name of this task connected to "Markov chain"
The main idea of that system is that the next state depends only on the current state, and there is a probability of transition.
First try shows, that one word phrases are shutting down the connection.
So we need to start with two word phrase. First hint is in the password:"talk_with_markov_about_positive_things".