About 0ld is g0ld
In this post, I’m writing a write-up for the machine 0ld is g0ld from Hack The Box. Hack The Box is an online platform to train your ethical hacking skills and penetration testing skills.
This challenge is worth 10 points and has a (very) easy difficulty. This challenge has a short description:
1 Old algorithms are not a waste, but are really precious...
If I read this description carefully, can I deduce that it is old encryption? Anyway, I’m on the business windshield… Let’s get to work!
Take the Challenge
I first downloaded the zip file and unzipped it with the password hackthebox. After the extraction of the archive, I have one file 0ld is g0ld.pdf.
1 2 3 4 ~$ unzip 0ld_is_g0ld.zip Archive: 0ld_is_g0ld.zip [keys.zip] 0ld_is_g0ld.pdf password: inflating: 0ld_is_g0ld.pdf
It seems that this file is password protected. I use the tool pdfcrack to crack the password of this PDF-file. I use the wordlist rockyou.txt. I invoked the command below:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 ~$ pdfcrack "0ld is g0ld.pdf" --wordlist=/usr/share/wordlists/rockyou.txt PDF version 1.6 Security Handler: Standard V: 2 R: 3 P: -1060 Length: 128 Encrypted Metadata: True FileID: 5c8f37d2a45eb64e9dbbf71ca3e86861 U: 9cba5cfb1c536f1384bba7458aae3f8100000000000000000000000000000000 O: 702cc7ced92b595274b7918dcb6dc74bedef6ef851b4b4b5b8c88732ba4dac0c Average Speed: 29963.7 w/s. Current Word: 'poopfart1' Average Speed: 15296.2 w/s. Current Word: 'juana1234' dAverage Speed: 30442.3 w/s. Current Word: 'may895' Average Speed: 31020.3 w/s. Current Word: 'HollyB090907' Average Speed: 30698.2 w/s. Current Word: 'william-jair' Average Speed: 30652.8 w/s. Current Word: 'tascione' Average Speed: 30576.7 w/s. Current Word: 'sausainis' Average Speed: 30687.5 w/s. Current Word: 'pomrakky' Average Speed: 30994.0 w/s. Current Word: 'naniiboi' Average Speed: 30155.2 w/s. Current Word: 'marah029' Average Speed: 28859.2 w/s. Current Word: 'ladanisuper' found user-password: 'jumanji69'
After a few minutes, the password is cracked
jumanji69. It wasn’t very difficult.
I opened the pdf-file and the question
Remember Me? got revealed with a nice picture of Samuel Morse, the founder of morse code. Morse was founded in the year 1835. So, old is indeed gold…
When I look at the bottom of the page, there is a morse code that needs to be decrypted.
1 .-. .---- .--. ... .- -- ..- ...-- .-.. -- ----- .-. ... ...--
I did some Googling on decode morse and found the answer to one of my favorite websites: https://www.dcode.fr/morse-code. I pasted the morse code and changed the setting to
USE THE FOLLOWING 2 CHARACTERS FOR SHORT AND LONG.
On the left side, the decrypted message is readable. I placed the answer in the right format and I have the flag for this challenge:
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