Posts DownUnderCTF
Post
Cancel

DownUnderCTF

On the spectrum

Description

My friend has been sending me lots of WAV files, I think he is trying to communicate with me, what is the message he sent?

Author: scsc

Attached files:

message_1.wav (sha256: 069dacbd6d6d5ed9c0228a6f94bbbec4086bcf70a4eb7a150f3be0e09862b5ed)

Solution

We can get the flag by using applications like audacity and view it on spectograms mode.

1.png

Flag

Flag : DUCTF{m4by3_n0t_s0_h1dd3n}


Leggos

Description

I <3 Pasta! I won’t tell you what my special secret sauce is though!

https://chal.duc.tf:30101

Author: Crem

Solution

If we inspect the element we can see the weird javascript in the homepage.

1.png The javascript code will be look like this:

1
2
3
4
5
6
7
8
9
10
11
12
document.onkeydown = function(e) {
    if (e.ctrlKey &&
        (e.keyCode === 67 ||
        e.keyCode === 86 ||
        e.keyCode === 85 ||
        e.keyCode === 117)) {
            alert('not allowed');
        return false;
    } else {
        return true;
    }
};

Then i setup a breakpoint at the if function. If we enter the wrong key (like right click on the mouse), we will be redirect to disableMouseRightClick.js where in that place will contain our flag for this challenge.

2.png 3.png

Flag

Flag : DUCTF{n0_k37chup_ju57_54uc3_r4w_54uc3_9873984579843}


formatting

Description

Its really easy, I promise

Files: formatting

Solution

If we run the file it will print :

1
2
nox237@nox237:~$ ./formatting
haha its not that easy}

But if we used command like “strings”, we will get the output like this

formatting_1.png

Then we can used ltrace to get the flag.

1
2
3
4
5
nox237@nox237:~$ ltrace ./formatting
sprintf("d1d_You_Just_ltrace_296faa2990ac"..., "%s%02x%02x%02x%02x%02x%02x%02x%0"..., "d1d_You_Just_ltrace_", 0x29, 0x6f, 0xaa, 0x29, 0x90, 0xac, 0xbc, 0x36) = 37
puts("haha its not that easy}"haha its not that easy}
)                           = 24
+++ exited (status 0) +++

Flag

Flag : DUCTF{d1d_You_Just_ltrace_296faa2990acbc36}