Linux Hacking: Binary & Hex | Leviathan: OverTheWire (Levels 3-4)

Key Takeaways

what's up everybody welcome back to their YouTube video my name is John Hammond and we're still looking at Leviathan from the over the wire war game so we just got the password for Leviathan level 3 the third level on the war game so let's go ahead and connect to this level alright now that we are in let's see what we've got here we've got a another set UID binary we can tell because it's noted red here and if we check out the permissions with LS tak helm and see the S bit so it is set UID binary Leviathan 4 is the command or the user that we will elevate to once we kind of run that binary as a command so level 3 enter the password what I don't know the password ok it's probably wanting a string so let's run strings on this we can pipe that to less so we can look through a little bit better there's a you've got shell notification a word Karl secret maybe secret is the password let's find out nope okay let's run L trace on it just had we had in some other levels string compare ho no 3-3 and what why is that happening we didn't do anything with that whatsoever though we never supplied that data whatever whatever enter the password hello it compares hello with some hex values and runs string compare strcmp string compare hello newline and SNL printf new line okay well obviously that these two are not equal so if we let's try and run it with SNL printf level 3 password oh and we've got shell okay Who am I I'm Leviathan for perfect let us check out the password and move on it's kind of a simple solution on that one again a little bit of L trees let's break out of this note this has Leviathan for and connect now to Leviathan for let's jump in nothing in the home directory so let's check out it with hidden throught the hidden flag oh gosh the hidden flag I could end my and my youtube career just like that alright CD dot fresh let's check out that hidden folder there is a file called bin ok and bin is a set UID binary we can tell what it's red and when we run it it just prints out some binary thinks ok it doesn't look like it changes so what is this spelling out it's a but of 0 and ones it's clearly a message in binary it looks like these are sets of eight so it looks like these are bytes let's do some command-line kung-fu to figure out what this stuff really is we can throw this to a like ask you to hex calm but what's the fun in that let's go ahead and replace all of these spaces with newline characters so we can process them on each line and then let's do a little Wow read line so we can work with each of these in its own iteration and let's convert them with BC if you haven't heard of BC it I consider it like binary conversion but it is just a command-line I don't know whatever it will convert between basis base converter I like to think of it as we can say I want the ending base so output base equals 16 while the input base or I base equals 2 and then we'll pass in the line that we're working with here and then we will give that to BC cool so now we've got a bunch of hex and if we bring our lines back or if we remove those new lines just like we had before so now it's all online we can pass this to X X T attack or to reverse and tack P for the printable stuff and now we have some seemingly password like string here let's go ahead and save this oh I don't want that new shell let's let's go ahead and break out I'm pretty confident that's the password that is what life and 5 right yes so paste that in let's try to connect to Leviathan 5 with that as our password and we are in perfect ok so that was the password so I did a little bit of a command-line kung-fu there just read through each of those bytes that were displayed in binary converted them from base to to hexadecimal base 16 and I did that so I could just give them back to X XD and X XD as we've seen in at least bandit and other videos of other tutorials and guides and stuff like that that will take a hex dump so we were able to use the tax or and attack B to reverse it and put it back into ASCII and that got us the string so now we're into level 5 and we'll jump into that in the next video so thank you guys for watching I hope you're enjoying these I hope I'm not going too fast so if you're enjoying the content I hope you're learning a little bit if you haven't seen that stuff before but uh thanks again see you soon