Pico CTF

Secret of the Polygot

Description

The Network Operations Center (NOC) of your local institution picked up a suspicious file, they're getting conflicting information on what type of file it is. They've brought you in as an external expert to examine the file. Can you extract all the information from this strange file? Download the suspicious file is here.

Hints

  1. This problem can be solved by just opening the file in different ways

Solution

picoCTF{f1u3n7_1n_pn9_&_pdf_1f991f77}

CLI

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ ls
flag2of2-final.pdf secret_polygot.txt

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ cat flag2of2-final.pdf
�PNG
�
IHDR2?���iCCPICC profile(�}�=H�@�_S��;f�bAT�Q�P�
�Vh����/hҐ��8

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ file flag2of2-final.pdf
flag2of2-final.pdf: PNG image data, 50 x 50, 8-bit/color RGBA, non-interlaced

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ mv flag2of2-final.pdf flag2of2-final.png
kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ eog flag2of2-final.png

[1]+ Stopped eog flag2of2-final.png

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ exiftool flag2of2-final.png 
          ExifTool Version Number         : 12.40
          File Name                       : flag2of2-final.png
          Directory                       : .
          File Size                       : 3.3 KiB
          File Modification Date/Time     : 2024:12:26 15:20:46-08:00
          File Access Date/Time           : 2024:12:26 15:31:25-08:00
          File Inode Change Date/Time     : 2024:12:26 15:29:41-08:00
          File Permissions                : -rw-rw-r--
          File Type                       : PNG
          File Type Extension             : png
          MIME Type                       : image/png
          Image Width                     : 50
          Image Height                    : 50
          Bit Depth                       : 8
          Color Type                      : RGB with Alpha
          Compression                     : Deflate/Inflate
          Filter                          : Adaptive
          Interlace                       : Noninterlaced
          Profile Name                    : ICC profile
          Profile CMM Type                : Little CMS
          Profile Version                 : 4.3.0
          Profile Class                   : Display Device Profile
          Color Space Data                : RGB
          Profile Connection Space        : XYZ
          Profile Date Time               : 2023:11:02 17:42:31
          Profile File Signature          : acsp
          Primary Platform                : Apple Computer Inc.
          CMM Flags                       : Not Embedded, Independent
          Device Manufacturer             : 
          Device Model                    : 
          Device Attributes               : Reflective, Glossy, Positive, Color
          Rendering Intent                : Perceptual
          Connection Space Illuminant     : 0.9642 1 0.82491
          Profile Creator                 : Little CMS
          Profile ID                      : 0
          Profile Description             : GIMP built-in sRGB
          Profile Copyright               : Public Domain
          Media White Point               : 0.9642 1 0.82491
          Chromatic Adaptation            : 1.04788 0.02292 -0.05022 0.02959 0.99048 -0.01707 -0.00925 0.01508 0.75168
          Red Matrix Column               : 0.43604 0.22249 0.01392
          Blue Matrix Column              : 0.14305 0.06061 0.71393
          Green Matrix Column             : 0.38512 0.7169 0.09706
          Red Tone Reproduction Curve     : (Binary data 32 bytes, use -b option to extract)
          Green Tone Reproduction Curve   : (Binary data 32 bytes, use -b option to extract)
          Blue Tone Reproduction Curve    : (Binary data 32 bytes, use -b option to extract)
          Chromaticity Channels           : 3
          Chromaticity Colorant           : Unknown (0)
          Chromaticity Channel 1          : 0.64 0.33002
          Chromaticity Channel 2          : 0.3 0.60001
          Chromaticity Channel 3          : 0.15001 0.06
          Device Mfg Desc                 : GIMP
          Device Model Desc               : sRGB
          Pixels Per Unit X               : 11811
          Pixels Per Unit Y               : 11811
          Pixel Units                     : meters
          Modify Date                     : 2023:11:02 17:57:06
          Comment                         : Created with GIMP
          Warning                         : [minor] Trailer data after PNG IEND chunk
          Image Size                      : 50x50
          Megapixels                      : 0.003
kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ ghex flag2of2-final.png

Part 1 - picoCTF{f1u3n7_

kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ pdftotext flag2of2-final.pdf
kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ ls
flag2of2-final.png secret_polygot.txt
flag2of2-final.pdf flag2of2-final.txt
kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ pdftotext flag2of2-final.pdf
kappa@kappa-Aspire-Z5600:~/Desktop/Secret of Polygot$ cat flag2of2-final.txt

Part 2 - 1n_pn9_&_pdf_1f991f77}

(Part 1 + Part 2) = picoCTF{f1u3n7_1n_pn9_&_pdf_1f991f77}