| my rAnd0m m1ndfl0w |
| #whoami $bl0g /script.s |
Disobey 2020 - CTF - Steganography - The Boss Writeup ----------------------------------------------------- So this was probably the easiest stego for a while. Started by viewing the file with pinta and quickly just screwing around with curves. Seemed like there was nothing special there. Checked the metadata with exiftool: exiftool the_boss.jpg ExifTool Version Number : 10.80 File Name : the_boss.jpg Directory : the_boss File Size : 1688 kB File Modification Date/Time : 2020:02:14 13:51:39+02:00 File Access Date/Time : 2020:02:14 13:54:11+02:00 File Inode Change Date/Time : 2020:02:14 14:01:32+02:00 File Permissions : rw-rw-r-- File Type : JPEG File Type Extension : jpg MIME Type : image/jpeg JFIF Version : 1.01 Exif Byte Order : Little-endian (Intel, II) X Resolution : 72 Y Resolution : 72 Resolution Unit : inches Software : GIMP 2.10.12 Modify Date : 2019:09:09 20:42:46 Y Cb Cr Positioning : Centered Exposure Time : 1/30 F Number : 2.0 Exposure Program : Not Defined ISO : 370 Exif Version : 0220 Date/Time Original : 2018:04:15 10:06:22 Create Date : 2018:04:15 10:06:22 Components Configuration : Y, Cb, Cr, - Shutter Speed Value : 1/30 Aperture Value : 2.0 Brightness Value : 0.27 Metering Mode : Average Flash : Off, Did not fire Focal Length : 4.1 mm Sub Sec Time : 981434 Sub Sec Time Original : 981434 Sub Sec Time Digitized : 981434 Flashpix Version : 0100 Color Space : sRGB Exif Image Width : 3120 Exif Image Height : 4160 Sensing Method : One-chip color area Scene Type : Directly photographed Exposure Mode : Auto White Balance : Auto Focal Length In 35mm Format : 30 mm Scene Capture Type : Standard GPS Latitude : 0 deg 0' 0.00" GPS Longitude : 0 deg 0' 0.00" GPS Altitude : 0 m GPS Time Stamp : 05:06:22 GPS Img Direction Ref : Magnetic North GPS Img Direction : 82 GPS Date Stamp : 2018:04:15 Compression : JPEG (old-style) Photometric Interpretation : YCbCr Samples Per Pixel : 3 Thumbnail Offset : 930 Thumbnail Length : 11226 XMP Toolkit : Image::ExifTool 11.85 Api : 2.0 Platform : Linux Time Stamp : 1568054570453383 Version : 2.10.12 Digital Source Type : http://cv.iptc.org/newscodes/digitalsourcetype/digitalCapture Format : image/jpeg Rights : Q1RGe21ldDRkNHRhXzFzX2FfZzAwZF9yZXNvdXJjZX0K Model Release Status : None Creator Tool : GIMP 2.10 Document ID : gimp:docid:gimp:178c9126-5afb-4b74-9928-2a8bd3a2b5ec History Action : saved, saved History Changed : /metadata, / History Instance ID : xmp.iid:8c30ef0e-1861-4116-8e43-ecd6f6fef9a2, xmp.iid:23e4a653-be3a-4ebe-9939-5115cb50eb31 History Software Agent : Gimp 2.10 (Linux), Gimp 2.10 (Linux) History When : +02:00, +02:00 Instance ID : xmp.iid:47a5d7a1-315d-4bd4-893b-54081f09d64b Original Document ID : xmp.did:1d14c2e5-fefd-40d4-a9f2-50378f87f355 Profile CMM Type : Unknown (lcms) Profile Version : 4.3.0 Profile Class : Display Device Profile Color Space Data : RGB Profile Connection Space : XYZ Profile Date Time : 2019:09:09 18:42:29 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 : Unknown (lcms) 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 Image Width : 3120 Image Height : 4160 Encoding Process : Progressive DCT, Huffman coding Bits Per Sample : 8 Color Components : 3 Y Cb Cr Sub Sampling : YCbCr4:4:4 (1 1) Aperture : 2.0 GPS Date/Time : 2018:04:15 05:06:22Z Image Size : 3120x4160 Megapixels : 13.0 Scale Factor To 35 mm Equivalent: 7.3 Shutter Speed : 1/30 Create Date : 2018:04:15 10:06:22.981434 Date/Time Original : 2018:04:15 10:06:22.981434 Modify Date : 2019:09:09 20:42:46.981434 Thumbnail Image : (Binary data 11226 bytes, use -b option to extract) Circle Of Confusion : 0.004 mm Field Of View : 61.9 deg Focal Length : 4.1 mm (35 mm equivalent: 30.0 mm) GPS Position : 0 deg 0' 0.00", 0 deg 0' 0.00" Hyperfocal Distance : 2.06 m Light Value : 5.0 Rights looks like base64:
echo Q1RGe21ldDRkNHRhXzFzX2FfZzAwZF9yZXNvdXJjZX0K|base64 -d
CTF{met4d4ta_1s_a_g00d_resource}
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