 What is up everybody? My name is John Hammond. Welcome back from the YouTube video still looking at the Google capture flag competition Some of the beginners quest challenges before I get started. I want to shout out to live overflow I know I've been doing this a little bit all the time, but I want to really reiterate He's awesome Was willing to hang out with me and play this capture flag competition with me So if you haven't seen him on YouTube check out his channel and hopefully we'll be able to do some cool stuff together again really soon So let's jump in I wanted to cover another beginners quest challenge up at the top here This challenge is called firmware. It's a reverse engineering challenge supposedly, but I don't really think so It's not classic reverse engineering It's just messing around with a file system because of firmware. So let's go ahead and download this I'll put this in GCTF my folder for the game and Create a folder for the challenge itself called firmware. We can save the file let's go ahead and Open up a terminal so we can see what we're working with here CD into firmware Let's see what this thing is. It's again a zip archive as Most everything we've seen so far. Let's call this firmware zip CD from where No, no, I'm sorry. You don't want to CD into a zip archive. You want to unzip it and We have challenge.exe for that GZ. Let's gun zip that challenge for And this takes a little bit of time, but looks like it came back So we have challenge EXT4 and it is a file system I tried it for the longest time to bin walk tacky this and I don't recommend it because it is literally unpacking a file system and it took up a lot of gigabytes and like Stopped took up all the space on my hard drive and stopped my screen capture while I was trying to cold Cold record and get myself going through the game live So it it warns you large files huge files. Don't try and extract this thing So what I ended up doing was opening up My file explorer Nautilus and I clicked on challenge.exe 4 what you can do is you can right click and I wanted to try and mount it. I think That's what I did. I didn't I didn't end up going through this. No what I did was I mounted it I Mounted challenge dot EXT4 on to media John and and I got to run that as root, but It figured it out cool, and then I went over to media John and Now I have a file system, but And I looked at this and all the hidden files. I saw this interesting media PC back gore.gz, so I tried to gun zip that and I need to be root to do that because it's a new interesting place now if I LSTAC L or LSTAC A sorry I have this file that we can cat out and There's a flag just like that. So weird challenge Didn't end up extracting it, but I ended up mounting it. I'm sorry. I kind of forgot it I looked at Nautilus normally you can if you wanted to you can try and mount it through the file system And through your file explorer and a GUI, but I did it just like that with the command line And it was able to take it a okay for me. So let's note that the flag there Let's go back to GCTF firmware Take note of the flag in that in that directory and mark this challenge as complete So not insanely difficult. I didn't want to go down the rabbit hole or show you guys that rabbit hole When you look at the entire file system because I went into home for a while. There was nothing there I tried to look around in the binaries see if there was anything there anything out of ordinary but Got to remember to check those hidden files literally everywhere Even just control H when you got your file explorer open It'll show you those hidden files and always be using LSTAC A Show all the hidden files because you have no idea what might be trying to sneak under your nose So thank you guys for watching. Hope you're enjoying this. I hope you're enjoying these videos Another shout-out to live overflow super cool guy check out his YouTube content If you're liking what I do if you're liking this video, please drop a like hit that button If you're willing to write out a comment, let me know what you think But else you'd like to see it'd be awesome if you were willing to subscribe and that means the world to me So thanks again. See you soon