Juniors CTF 2016 :: Black Suprematic Square

Key Takeaways

all right hello everyone welcome back to the YouTube video my name is John Hammond and this time around I want to be showcasing some of the challenges from the junior CTF which was going on this past weekend so honestly I I had a lot of fun of the CTF I think I've plateaued right now currently we're at thirteenth place I guess okay yeah tied for 13 we've been fluctuating the highest I goddess was about third place and I proof of that I do i do have I do have proof of that I'll showcase a little photo here we were doing well up at the top for a little bit but I plateaued I can't solve any more challenges so I'll try and review and showcase demonstrate the stuff that I did solve and we'll move along so honestly not the best CTF and that there was a whole lot of guessing and there were a lot of language barriers so I kind of struggled with some of the challenges and stuff but I still I wanted to show them off to you the ones that I did solve so the first one that was apparently a trivial web task which I struggled for a little bit because it's just his image no description and I had googled this I had like Google reverse image searched it I down a little bit right exit tool for most been walk all the usual low-hanging fruit to see like what bag it was but it's just a web challenge but there was no website or web link or anything so I didn't think to look at the web source or like the HTML of this web page but once you do that you'll notice okay here's the challenge and everything and there's two images here one of which is actually visible to us which is this guy so I'll copy that link let's crank it out and there is the actual image that's being presented to us but this width equals 0 is obviously hidden behind that other image so that has to be something interesting and there it is it's so believe it or not this is our flag which I guess I mean you just have to assume that there is no flag format for the CTF also so that's a good a good real good thumbs up for the CTF really good and I'll just save this as juniors so of course you'd have to type this all out by hand and try and correct it if you try and submit that if you wanted to and that was also a a fun thing that I had to do with some other challenges to news all right thing and I'll just save it so when we actually get in there you would type this all out but to avoid that I try to just run like tesseract on it and I was able to do some OCR and I like optical character recognition and you could actually see it so what is able to get this all out and then I just T deed sorry TR delete all new lines and that would be the flag but this is not foolproof this does have some miss Crevan sees like this o is actually a zero so I didn't want to type it all out but i just looked through it and tried to find the mistakes and i ended up submitting that as the flag so silly thing should have known to view the source as a web challenge but I didn't think I thought they would like Lincoln me to an actual website it wouldn't be in the challenge description itself so on on that but I did end up solving the challenge and tesseract is a really cool thing to do OCR if you haven't heard of it tesseract OCR yeah so definitely check that out if you haven't seen it before optical character recognition is pretty nice for when you have a bunch of stuff and an image and you can't like copy and paste that you don't have to type it out by hand so yeah thanks for watching guys hope you enjoyed this one really simple really easy first couple of challenges are apparently they said these tasks are not supposed to be difficult they're all designed for school teams I didn't solve a whole lot but I will showcase the ones that i did get and demonstrate them for you guys so thanks for watching I'll see you in the next video