Hmm images distorted with some black pixels, my first try was to try Stegsolve on the images, nothing :(

Let’s try some Hue, contrast and bit manipulation using Photoshop, I tried on different channels, still no luck. Let’s try to combine them and…

Yesss.!!! Success

So we get the link

Level 3

Let’s open the link, And we are presented with a page with some blocks, each block having array of circles when hovered shows a gray circle or a circle with bitcoin cash image.

So I need all of them in hovered state, I tried to fondle with the source, I observed that it had tables with cell with class='o' for the BTC icons, I tried fiddling with JavaScript in Google’s developer console, but I was unable to force all of them in hovered state, so I got back the simple technique let’s save the page. And I got a single HTML page. Let’s see the HTML

Ahh, so I just added two lines on td.o block

And I got this

So we get Y5nNvfl.png, since the OP used Imgur for the the images, lets open it, nope no image found. Let’s go back to the error correction of the OP,

“I was going through the puzzle once again with a fresh mind this morning and found one critical mistake. Please take a look here and you will know when you need it” — OP

Okay so l=I Changing it gives Y5nNvfI.png which works.

Level 4

Let’s see the image:

So various cryptocurrencies logos with a . [dot] in the middle possibly link to another .png image. Lets see what each logo represent, Apart from ethereum I knew none none of the cryptocurrencies. So after a bit of googling I got to this site.

It had all the cryptocurrencies with its name and logo. Decoding each gives

First letter of each cryptocurrencies gives us ewwfroa.png

But Imgur links are case sensitive and opening ewwfroa.png on Imgur doesn’t works. So we need to try all the Case combinations for the string ewwfroa and test if it’s valid or not.

So I thought of creating a simple Python script to do my job. Let’s test what Imgur returns for valid and invalid image links

So it gives 302 for invalid links and 200 for valid image links. So let’s make a simple script to automate our job

Running this gives us

So only one link, great! lets open it and it works

Level 5

So last part :D , let’s open the image

Hmm lots of same QR Code, lets use Photoshop and get the QR Code out

Decoding it gives us http://www.q5g.nl , opening it gives us blank page with its source code containing link to another site, opening another site and it’s seems some Netherlands’ site for coins. I tried to find something within the page source codes, tried to check if there was any open port to fiddle with, no success. Maybe I am going in the wrong direction.

So I got back to the image again, opened it in Photoshop fiddled with it, nothing :/

Let’s see if there is something hidden using steganography. I will use Stegsolve.

Ah, we find the wallet seed and its QR code in the “0 bit” planes.

Muhahahaha..!!

Now all was left to access the wallet using the wallet seed and transfer the BCH to another wallet :P

Thanks to the OP agregat for the fun puzzle. Made me learn quite a lot, especially about cryptocurrencies. And..