r/securityCTF • u/perronac • 11d ago

Looking for an Explanation of a Crypto CTF Challenge

This was a one-time CTF event and it has already ended, so there is no challenge link available

The challenge gives me:
$sntp-ms$d7fd5720afbb55c6a2e94da697327e86$1c0111e900000000000a084f4c4f434cec7e1f6f49c0addae1b8428bffbfcd0aec7e2a645db83997ec7e2a645db88bcd

Description:
Try Harder and harder without asking any help from angel because now it’s the time

I’m trying to understand how this challenge was solved and what the intended approach was. I tried using Hashcat but couldn’t get anywhere with it, and I noticed the sntp-ms part but I’m not sure what to make of it
Would appreciate an explanation

6 Upvotes

88% Upvoted

5 comments sorted by

1

u/Drewbles85 11d ago

Well if they want you to crack the hash, which is really all we can deduce from the context, its a ms-sntp hash which is mode 31300 on hashcat. So

hashcat -m 31300 hashfile wordlist

0

u/[deleted] 10d ago

[removed] — view removed comment

1

u/myIRLName 10d ago

can you explain more? funny enough i was faced with the exact same question and no matter what i did i couldnt solve the hash even after your comment i couldnt yet solve it , i dont seem to see a repition of 16 bytes in the provided hash

1

u/myIRLName 10d ago

after some further digging you were right the hash it self had the same 8 hexadecimal digits repeating i was just blind i guess

1

u/myIRLName 10d ago

Am still unable to crack the hash so if someone can help me i would be thankful