CTF collection Vol.1

1. What does the base said?

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BY the given encoded, we know that this is BASE 64 VEhNe2p1NTdfZDNjMGQzXzdoM19iNDUzfQ==

So, heat up our "oven" CyberChef

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Flag: THM{ju57_d3c0d3_7h3_b453}

2. Meta Meta

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This is the given picture. (Find Me.jpg)

Findme

Hint is in the title itself. Meta = Metadata. Usually I will use exiftool in linux. But, today i want to share new online tools for exiftool.

metapicz

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Flag: THM{3x1f_0r_3x17}

3. Mon, are we going to be okay

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This is the picture that they give.

Extinction

Well, just try online stega tools.

Steganographic Decoder

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Flag: THM{500n3r_0r_l473r_17_15_0ur_7urn}

4. Erm......Magick

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This was like free flag. i didn't mean to get this one. Lucky I found it.

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Flag: THM{wh173_fl46}

5. QRrrrr

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They give QR Code. So, just find QR Code Decode

ZXing Decoder Online

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Flag: THM{qr_m4k3_l1f3_345y}

6. Reverse it or read it?

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I try to run this file.

./hello.hello

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But I didn't get anything. Just a simple hello. So. I try to read this file by run this command

strings hello.hello

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Flag: THM{345y_f1nd_345y_60}

7. Another decoding stuff

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I try Magic in CyberChef 3agrSy1CewF9v8ukcSkPSYm3oKUoByUpKG4L

It's Base 58.

CyberChef

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Flag: THM{17_h45_l3553r_l3773r5}

8. Left or right

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MAF{atbe_max_vtxltk}

"Rot 13 is too mainstream" but we sure that this is Rot something. So, using cyberchef, rot until found the flag. It is Rot 33.

CyberChef

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Flag: THM{hail_the_caesar}

9. Make a comment

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We have no source for this challenge. Why don't we check "Inspect".

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Flag: THM{4lw4y5_ch3ck_7h3_c0m3mn7}

10. Can you fix it?

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He said he messed up with this PNG file. So, we open up HxD/hexeditor to check the header/footer of this file.

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Yaa, he messed it up. As we can see, wrong header.

Search List of signatures

This is a signature header for PNG file.

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Change and save it.

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repair

Flag: THM{y35_w3_c4n}

11. Read it

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Find all possible tryhackme account until it lead too tryhackme reddit account where the flag is.

tryhackme - reddit

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Flag: THM{50c14l_4cc0un7_15_p4r7_0f_051n7}

12. Spin my head

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++++++++++[>+>+++>+++++++>++++++++++<<<<-]>>>++++++++++++++.------------.+++++.>+++++++++++++++++++++++.<<++++++++++++++++++.>>-------------------.---------.++++++++++++++.++++++++++++.<++++++++++++++++++.+++++++++.<+++.+.>----.>++++.

This is Brain Fuck

Find Online tools.

Brainfuck

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Flag: THM{0h_my_h34d}

13. An exclusive!

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S1: 44585d6b2368737c65252166234f20626d S2: 1010101010101010101010101010101010

By using CyberChef, we try Hex then XOR.

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Flag: THM{3xclu51v3_0r}

14. Binary Walk

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So, fire up our kali to Binwalk this file

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binwalk -e hell.jpg

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Flag: THM{y0u_w4lk_m3_0u7}

15. Darkness

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"Lurking in the dark" it sounds like a hint. I try using Stegsolve

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Flag: THM{7h3r3_15_h0p3_1n_7h3_d4rkn355}

16. A sounding QR

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Well, just try QR Decode online tools. ZXing Decoder Online

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We get link after decode. https://soundcloud.com/user-86667759/thm-ctf-vol1

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Flag: THM{SOUNDINGQR}

17. Dig up the past

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I go to the link. https://www.embeddedhacker.com/

But, unfortunately! We don’t get anything for the given date. https://www.embeddedhacker.com/2020/01/hacking-walkthrough-ctflearn-crypto-medium/

Well, I need hint.

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Erm, Wayback Machine. Okay, Mr Google. I need your help.

Wayback Machine

Put in our link that was given from the challenge.

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Find January 2, 2020 from the calendar.

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Click on 13:12:52. Scroll until found our flag.

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Flag: THM{ch3ck_th3_h4ckb4ck}

18. Uncrackable!

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MYKAHODTQ{RVG_YVGGK_FAL_WXF} . Well, seems like vigenere without a key to me.

Vigenere Solver

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Flag: TRYHACKME{YOU_FOUND_THE_KEY}

19. Small Bases

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581695969015253365094191591547859387620042736036246486373595515576333693

First, I decode Decimal-Hex

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Then, Hex-Ascii

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Flag: THM{17_ju57_4n_0rd1n4ry_b4535}

20. Read the packet

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Open up pcap file using Wireshark

Then, File - Export object - HTTP

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Click on flag.txt – Save

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Flag: THM{d0_n07_574lk_m3}

DONE!!

Thank you for reading my writeup.

By AdaniKamal