Homemade CTF Challenge: 06 "I lost my password!"

Key Takeaways

hello everyone welcome back to another simple and short video uh explaining and depicting how I created and solved some of the challenges that I put together for a local Capture the Flag competition for uh my school cyber team so uh I'm actually going to skip over the exor challenge because the way that I intended this to be solved was with a tool that we created inhouse um so I don't I don't I don't think I'll actually just demonstrate the one for you we'll just hop on over it and we'll move on to the I lost my password challenge so this one's pretty simple um it says okay oh no I've lost my password can you help me retrieve it and this actually isn't in the usual flag format it's just the password so you'd note here that we have a big Etc Shadow or Etc uh Etc password file um and it's actually already unshadowed for us Etc Shadow doesn't hide the hash with a star we see the full hash of this user John which is meant to be a hint that oh you should be using the John the Ripper utility to actually go ahead and solve this so um we would actually go ahead and download this I'll hop over to my terminal to kind of explain how we run through it so I'll HP over to I lost my password and there's our hashes so what I would end up doing is actually using John the Ripper which if you have not heard of him uh I recommend doing some research because the whole point of the CTF was to show off um John the Ripper as the password cracker so so other individuals get to know this tool and know that it exists and how to use it that kind of thing so um we do want to be able to crack the password and we're going to do a dictionary attack because a Brute Force attack is very long it would make more sense to initially use a dictionary file so uh that was the tactic that I wanted them to kind of hopefully figure out but the way we end up using a dictionary file with John is actually using a word list which I think we denote with dasl or Dash list maybe yeah word list so you can use the word list and we I'm going to set that equal to where I store The Rock you. text file and then I just give it the hashes and looks like it already created this I might have it in my home folder on let's just remove those so now I'd be able to run the program just fine and it's got to be in dictionary files that's where I actually store the rocku text file and if you haven't heard if you haven't seen it or heard of it before John the Ripper dictionary files one of those sites that I ended up seeing on sack overflow they note that Rowan boughs has a lot of good password lists and I think they say that rock you. text is pretty much the best list available you probably can't see that it's super small but it's huge and it's stolen unencrypted stuff so all right so John the Ripper is finished and it's noted that white rose is the password so just is a simple brute force uh not not not Brute Force but a a dictionary attack on it so white rose would be the password of the user which we just managed to uh crack and we would submit that as our flag and we get that 100 points awesome so super easy again simple stuff just wanting to show off those tools like John the Ripper and how to use them and so the individual will suffer for a little bit if they've never seen it before and figure it out so uh and hopefully learn something in that process okay thanks for watching everyone I'll see you in the next video