DawgCTF 2023
Hi Mates!
I played this CTF as usually along with my team Invaders0x1. During the competition, my team and I worked tirelessly without taking a break from Fri, 21 April 2023, 22:30 IST — Sun, 23 April 2023, 22:30 IST.
Proud to share our team ranked #Top6 globally in DawgCTF2023 which was hosted by UMBCCyberDawgs. We faced tough competition from some of the best teams in the world, but we were determined to succeed. Despite the difficulty of the task, our team persevered and came up with a creative solution.
Overall, we are grateful for the experience and proud of our achievement. We will continue to work hard and strive for excellence in future competitions.
Our team knows that #persistence is key to success, and we will continue to demonstrate that in everything we do.
Here are some of the challenges I have solved :
Breaker, Breaker #
I got this radio recording of a local police department using my trusty scanner, can you figure out what all those fancy numbers mean?
(The flag will be in alphabetical format only and you will enclose it in DawgCTF, i.e DawgCTF{FLAGGERT}
After downloading the 40-second audio file, I have been listening to this audio for nearly 1 hour in an attempt to understand and identify the number digits in the audio.
However, I have not been successful in identifying the exact number digits. As a result, I decided to use online tools like Flixier to generate a transcript (i.e., convert audio to text), but it gave worse results than what I was able to do myself 🥲.
Again I was decided to do myself. And the result is
Step-1: [10-1-8, 10-7, 10-0, 10-17, 10-15, 10-4, 10-0, 10-1-7, 10-18 And 65 ]
Step-2: [10-18, 10-7, 10-0, 10-17, 10-15, 10-4, 10-0, 10-17, 10-18 And 65]
Step-3: [18, 7, 0, 17, 15, 4, 0, 17, 18 And 65]
Step-4: [18, 7, 0, 17, 15, 4, 0, 17, 18, A]
Here 65 is the hint, i.e., 65 = A in ASCII
After spending whole day with different ways to decode the sequence,
Finally figured something good.
i.e., Add 65 to all numbers
Step-5: [18+65 7+65 0+65 17+65 15+65 4+65 0+65 17+65 18+65]
Step-6: [ 83 72 65 82 80 69 65 82 83 ]
To convert Decimal to Ascii :
decimal_values = [83, 72, 65, 82, 80, 69, 65, 82, 83]
ascii_string = ''.join([chr(decimal) for decimal in decimal_values])
print(ascii_string)
Output : S H A R P E A R S
Flag : DawgCTF{SHARPEARS}
Oh, Deer #
My friend sent me a bunch of pictures of deer and said there's a secret code in them or something. Can you figure out what he's talking about? He mentioned something about going from left to right in order and that there's only two types of a thing in all the pictures. He also said that it's not zeroes and ones, but wouldn't tell me what other two things it would be if not zero and one.
The flag will be in the format DawgCTF{THEFLAG}, alphabetical only, all capitals for the contents inside DawgCTF{}.
After extracting the ohdeer.zip file, we obtained 0-24 deer images, with each image containing 2 deers.
By observing the images, we can differentiate between the sexes of the deer.
From left to right:
(F) (M)
(M) (F)
(M) (M)
(F) (F)
We have obtained the final sequence form all images :
FM MF MF MM MF MF FF MF FM FF FM FF FF MM FM FF FM MF FM FF FF MF FM FF FM
This is the Baconian Cipher,
FMMFM FMMMF MFFFM FFMFF FMFFF FMMFM FFFMM FFMFF FFMFF MFFFM
Using dCode we can decrypt Cipher text and obtain Plain text
N O R E I N D E E R
And here is the flag,
Flag : DawgCTF{NOREINDEER}
Yo Dawg #
Yo Dawg, we heard you like flags, so we put a flag in your memes.
Using command : exiftool yo_dawg.jpg
m4r10@ARLinux:~/Desktop/CyberSec/CTF/DawgCTF/forensic$ exiftool yo_dawg.jpg
ExifTool Version Number : 12.40
File Name : yo_dawg.jpg
Directory : .
File Size : 41 KiB
File Modification Date/Time : 2023:04:22 10:49:38+05:30
File Access Date/Time : 2023:04:22 10:52:46+05:30
File Inode Change Date/Time : 2023:04:22 10:50:01+05:30
File Permissions : -rw-rw-r--
File Type : JPEG
File Type Extension : jpg
MIME Type : image/jpeg
JFIF Version : 1.01
Resolution Unit : None
X Resolution : 72
Y Resolution : 72
Image Width : 622
Image Height : 401
Encoding Process : Baseline DCT, Huffman coding
Bits Per Sample : 8
Color Components : 3
Y Cb Cr Sub Sampling : YCbCr4:2:0 (2 2)
Image Size : 622x401
Megapixels : 0.249
By using stegsolver
We can,
Analyze color channels to identify hidden data,
Extract and analyzing metadata embedded in the image file,
Apply various filters to the image to highlight hidden information,
Check for unusual patterns or anomalies in the image.
Finally, After changing the Frame obtained the flag.
And the flag is,
Flag : DawgCTF{h342d_y0u_11k3_f1495_d4w9}