Mission Impossible

HTB Content Challenges
1

Hi mates,

Can someone of the 12 solvers of Mission Impossible contact me by DM to ask a question?

I have already solved the first part, but I am finding problems in solving the second.

Very much appreciated!!!
Best regards :slight_smile:

2

hey broā€¦

3

Same here. Got the first part and already have done some coding for the second but now Iā€™m stuck a bit. Donā€™t want to spoil here too much. Could someone PM me, please? A hint is much appreciated :slight_smile:

4

Working on the second part of this as well. I think I know the attack method based on the name dropped in the initial decoded message and the error message the server gives when your ā€œsomethingā€ is incorrect.

Edit: Got it. I was correct about the attack method. Just had to use a different library. :wink:

5

I have no clue about how to even start with this challenge, anyone want to help me with a first push? Aiming to finish up these crypto challenges but I donā€™t even see how I would use this one huge number, assuming it is a number.

6

Hi, Iā€™m on the second part of the challenge. Iā€™m pretty sure about the method, but probably Iā€™m doing something wrong.

The method takes ā€œsome timeā€ā€¦ and the web service gets always closed after a whileā€¦

It is normal that the attack takes so long (and in this case how can I prevent the server for closing?) or Iā€™m doing something wrong?

Thanks!

7

Did it, there was a bug in my script. It took some time anyway, but session was on enough to solve it.

8

I need serious help with this, I donā€™t know how to do the first bit

9

Anyone willing to share a hint on the first bit? Idea it is a xor encryption. Decrypting by trying to guess the first header and then guessing the rest of the content slowly while building a key - but it doesnā€™t seem to work with common headers

EDIT: Almost. Finally got the first bit.

10

Iā€™ve tried a bunch of different things on the initial message and nothing seems to coming out of it. Would someone mind DMā€™ing me a hint? Not even the direct answer, but just a rough directly would be appreciated!

11

This seems to be one of the toughest challenges everā€¦as the name says thoughā€¦

12

To anyone who solved the last part: How long did it take to decrypt the message? Oh man, itā€™s so slowā€¦

EDIT: Finally got it. 19077 queries. ā– ā– ā– . I loved this challenge.

13

I could really use a push on the first part of this challenge. The usual methods donā€™t seem to work.

14

i have literally no idea of how to start the challenge, can smb DM me on how to start. Iā€™ll rly appreciate it

15

Type your comment> @Ugi said:

I could really use a push on the first part of this challenge. The usual methods donā€™t seem to work.

I used a very basic, usual method for the first part. Consider all possible ways of analyzing the ciphertext.

16

I canā€™t decode the message file. Can someone give any clue?

17

Really liked this challenge. Techniques for both parts were new for me and I learned lots, although I lost my weekend :slight_smile:

18

This is a nice straightforward challenge. I probably made around 1.5 million queries before I stopped and verified my code and found a silly mistake ( I base64 decoded an initial hex encoded data ĀÆ_(惄)_/ĀÆ ) After fixing the mistake it took about 19000 queries to find the flag.

I am curious how the challenge was constructed. The paper suggests that it should take around 1 million queries, but this challenge requires 19000 only. It is highly unlikely to be a random occurence. Is there a way to construct this kind of challenge with any given complexity, or was it a trial and error approach?

19

Took almost 3 hours on my slow machine :frowning: Had to code in a way to reconnect to new HTB docker since the instances kept dying on me

20

Hi all , cannot even start this challenge, outlook element wonā€™t open, could anyone mp an hint plz ? ty