Official Block Hunt3r Discussion

Especially the headache…
Just a question,what data are you searching with your algorithm?

Type your comment> @ElleuchX1 said:

Especially the headache…
Just a question,what data are you searching with your algorithm?

The data you were referring to in your first post. You’re on the right track with that. But there’s a fair bit of it to go through. I automated the process with code. I’m not sure how I would’ve done it otherwise. It is an OSINT challenge, though, so maybe there’s a way.

There is definetely a painless way of exploring the blockchain.

Hint: If you would have to explore an entire blockchain searching for a malicious file, would you use the same approach you’re using? Research is the key.

Pd: you can do it in minutes with the right tools.

completely clueless with this one. On Discord, people were talking about using API’s and their own codes - but I’m lost as to how to even get started with this one

An interesting challenge, a mix of stego and forensic. I suggest to download geth and run a sync ( geth --goerli ), it only takes couple of hours because this is testnet. Then you can easily query whatever you want againt your local node

Type your comment> @joeblogg801 said:

An interesting challenge, a mix of stego and forensic. I suggest to download geth and run a sync ( geth --goerli ), it only takes couple of hours because this is testnet. Then you can easily query whatever you want againt your local node

You’ll need some patience. There’s only one peer (seed) and it takes a while to connect to it.

Finish,
I thing that I do not get the smartest path, but I learned a couple of new things.
Nice Challenge congrats to @Sm4rtK1dz to the challenge, was a huge journey.

No hint needed here, the chall description is enough in order to understand what you have to do.
There are at least three ways of approaching that:

The worst (mine): automatize all the manual tasks by some scraping. (functional but not recommended)

The intended: OSINT / Forensics / stego, you not need to understand the blockchain in depth, just a little bit, the basis.
Search what you need and use it.

A good practice: Learn the blockchain, learn methods and tools, run your node and make all the query that you want.

Thank you to @ Sm4rtK1dz, respect.

Hi, if someone can DM me. i have found the good bloc, and the data…but impossible to display it

Nvm, finished

@balatak said:
How big is the Görli data you download with geth --goerli?
You can use another service with api to download only what you need. And it’s more quickly.

The data set is about 5Gb I believe, it takes couple of hours to sync

Just posting to comment that you don’t ‘have’ to download the full data set - I put off doing this for ages as the comments about having to d/load 5Gb of data put me off. There is a way to remotely query for what you need but you can manually limit the range of data with some very basic trial and error experimentation - this should give you a much more manageable data set. Then you have to think how to search for the type of data you’re looking for. There are still a couple of gotchas after that! I found this hard and took me well out of my comfort zone but was very happy when I finally cracked it - thanks @Sm4rtK1dz
I’d love to see how other people solved this as I bet there are a few different ways.

@JennyCide I found the image, but i am must doing something wrong or i am missing one step because i cant see the picture. Right now i am not on my main box when i am posting this. I will try more stuff but if i got stuck i will PM you what i have just to tell me if i am right or not.

PS. NO need i was stupid.

Can I send someone a DM, I have half of the flag, but at a total loss for the other half…
Finally got it… jeez what a great challenge to overthink…

Hi all.

I would appreciate some help about this one.

I’ve already established the range of blocks I have to investigate
(the old-fashioned way, I have to confess) using etherscan.io.

I’ve been reading about Ethereum, played with Python and Web3,
and now I’m waiting for geth --goerli to finish syncing a LOT
of information and it’s taking forever).

I already have some sort of a plan of attack but would need
to access the blocks of interest using Python (in my case) to avoid
a manual search (hence the geth --goerli above).

But I see some of you say you were overthinking this one, and
that’s what I usually do so… any subtle no-spoiler hint you can share?

Thanks!

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Type your comment> @hedylamarr1914 said:

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you can solve it working hard, or using someone else’s work :smile:
No need to sync the blockchain, think about it as a database. :wink:

Quite a nice challenge this. It made me want to pull my hair out at first but with some research I managed to get there in the end. GitHub - vosnet-cyber/geffy: A Go-Ethereum blockchain data parser to look for images embedded in the chain - might help you a little

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I’m at the end of this challenge and I’m stuck on reversing the text back into an image, I’m using xxd with -r -p and every time I re-assemble it I can’t open the image with “Metadata can`t be loaded” I feel like I’m going insane trying to get this last bit to work, any hints?