Follow The Rabbit Hole

Challenge

Follow the rabbit hole and get the flag.

http://167.71.246.232/

Alternate URL: http://167.71.246.232:8080/rabbit_hole.php

Solution

Automation request with PowerShell Script and print the content.

$req='cE4g5bWZtYCuovEgYSO1';
do{
    $res = Invoke-WebRequest -Uri ('http://167.71.246.232:8080/rabbit_hole.php?page='+$req.Trim());
    Write-Output $res.Content >> rabbit_hole.log;
    $req = $res.Content.Split(']')[1];
} while($res.Content -ne 3);

56KB

rabbit_hole.log

In VSCode I selected all lines with '[' and past in another file removing all '[' and ']'. I saw that numbers in begging at line was possible index and the rest a simple HEX, then I sorted file.

17KB

code_sorted.txt

And finally I concatenated HEX in another file.

5KB

HEX.txt

The firsts 8 HEX's - 89 50 4E 47 0D 0A 1A 0A - is the File Signature for PNG file. Changing the extension I get the flag.

Flag