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Day 01: Happy HACKvent 2020
Description
Welcome to this year’s HACKvent.
Attached you can find the “Official” invitation to the HackVent.
One of my very young Cyber Elves cut some parts of the card with his alpha scissors.
Have a great HACKvent,
– Santa
Solution
opening it in GIMP doesn’t lead anywhere, we see the code has been cut out with the “alpha scissors”:
but running exiftool gives us a hint
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$ exiftool dec1.png
ExifTool Version Number : 1.88
File Name : 1.png
Directory : writeupfiles
File Size : 2.5 MB
File Modification Date/Time : 2020:12:01 20:11:37+01:00
File Access Date/Time : 2020:12:01 20:13:25+01:00
File Inode Change Date/Time : 2020:12:01 20:11:37+01:00
File Permissions : rw-rw-r--
File Type : PNG
File Type Extension : png
MIME Type : image/png
Image Width : 1600
Image Height : 900
Bit Depth : 8
Color Type : RGB with Alpha
Compression : Deflate/Inflate
Filter : Adaptive
[..]
Background Color : 255 255 255
Pixels Per Unit X : 2835
Pixels Per Unit Y : 2835
Pixel Units : meters
Modify Date : 2020:11:17 07:39:19
Image Size : 1600x900
Megapixels : 1.4
Thumbnail Image : (Binary data 8609 bytes, use -b option to extract)
There is a thumbnail image embedded, lets see if that has more info in it!
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$ exiftool -b -ThumbnailImage dec1.png > dec1_thumbnail.png
Aha! we can still see the flag on here!
Flag
HV20{7vxFXB-ItHnqf-PuGNqZ}