Google CTF - BEGINNER Reverse Engineering w/ ANGR
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- čas přidán 27. 08. 2020
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Often the best way for the student to learn is when the teacher is learning too.
Well Said
true....
i agree, also thanks to Mr.John, the way he describe things is attractive ( if that the word ) and i like it.
i agree
Absolutely riwt
John Hammond,TheCyberMentor,Hackersploit,ippsec.
Beginner community is in love with u guys❤️
Most youtubers within the first 30 seconds of their videos = begging for likes and subs, John being genuine and honest "I couldn't do it and I had to look at the write up". I seriously appreciate people like you who are open and despite the fact that you've been doing this for 5+ years you are still learning and encouraging people to keep going by doing so. I realise this is an old video but I hope you know it still has a positive impact on people who are looking to get into this and start their journey into the complex world of security.
This is way better than reading a writeup
Recent subscriber but I wanted to just compliment you on how well you talk us through your videos and what it is you're actually up to! As a beginner, in almost every possible avenue, understanding is quite difficult sometimes without going away and doing my own research. Sometimes a 10 minute video turns into an hour with me trying to understand things. However, I came across your channel recently and wow. The way you break it down makes it so simple, so I don't necessarily need to understand all the syntax when you explain what its doing so well! Just a little thank you from you to me, you're definitely aiding my learning and re-motivating me to believe I can actually do this lol
I appreciate your transparency John! Everyone in this space is awkwardly trying to learn. Its nice to see that everyone doesn't just start at knowing it all. Practice still makes perfect.
DUDE JUST KEEEEEEP GOING ! best cybersec channel seriously, freaking love watching you do a CTF, i personally learned a lot from you, thanks a lot !
What an amazingly kind and positive comment. I’m not even John, but thank you for posting this!
This is awesome John. Loving seeing the learning process, that in itself is so helpful.
Also I love your wrap up summaries that summarize everything and just hammer the whole thing home. Thank you
im really enjoying this. keep it coming John! I have been watching and learning from you since your powershell series updates and the originals you first put out. 👊
It feels like you underestimate the experience we go through while watching this:) It was cool, thanks for the video!
Though this video is a little old now, I want to highlight that seeing and understanding your learning *PROCESS* is just as valuable, if not more so, than learning directly from you like usual. Though, while still very important, understanding how someone may undergo their learning process differently from you can be extremely beneficial! Great stuff as always John, cheers!
Thank you for all the work you do and uploading this AWESOME content!!
Please keep making more videos love what you do and love to learn from you. Thank you so much John.
So I'm new. Like I've got some IT experience but only in the last year have I really started my cybersecurity learning. And in the last month started doing ANYTHING with CTFs. And as discouraging as it is for me having to look things up, you being transparent about it is just encouraging. Thank you.
As a newbie to cyber security and Ctfs, I really enjoyed this video. Thanks John!
I like you showing the actual magic behind the curtains. please do more of these they are very benefial
So educative.He makes hard things look easy. Your awesome John
You learning on the go, is far from boring - I work now almost 12 years in the field (not ethical Hacking or the sort) however, it is good to see and learn from other how to navigate and lern. I try to get my feet wet with CTF's - Ethical Hacking - Pen-Testing and your videos are so motivating, you boil it down to the essence, never stop learning never stop poking and get your hands dirty! Learn from others and especially from your own mistakes!!! Love the content you put out there! It's so valuable!!!
You make great videos. I hope you never stop making them.
Hey John, thank you so much, this is really informative and helpful. I like all your videos, and I learn alot from you.
That’s a nice video, interesting to see something challenging while learning. Good job at presenting!
I love your videos!!! It helps me to understand better ways to think through things
John I actually find watching you work through a problem you don’t know very very helpful. As a beginner It gives me an example of how to teach myself...? Does this make sense? Any way thank you my guy!
I like how i can use bits i dont understand to develop other parts of my life. Abstract but calming and sometimes effective. Always begin.
I mean even the basic concept of ANGR or Normal anger in real real life and basically running anger scenario and imagined results, effects and consequences of it. [address-failure or success] =x/x x2x but or No r- m:all
It is just letting me do whatever this was.
Talking at Top List even if he has asked No( )of it!
Edit: I think it was correct to post even if it wrong at it. But philosophically I all ready know this, but still I add value to flag. I honor- it.
-What i really meant to say was that I find it useful even if I will never write a Single code in my life.
So rad. Dude you're awesome. Thanks for learning like most of us do and being brave enough to do do it on camera.
Using angr in anger.
Love the step-by-step with thoughts and why!
This is so helpful John. I appreciate you very much my man. Keep it up
Thanks for sharing angr with us! Very insightful.
This was very helpful. I need to learn more about reverse engineering myself
"Solved this with anger" probably describes most debugging/reverse engineering successes
Gotta love the honesty. A lot of this low level binex stuff can shatter your self esteem when all you see is just the wins everywhere. It's good to see someone showing the learning process too
These videos are so great. Knowing how to code would probably make them even better 😂
Liked it.
Thanks for showcasing this one. It was the problem I spent most time on and couldn't beat it. This technique will go away in the vault for next time.
As you said the best way to learn things are to learn from writeups. awesome channel this is.
I love to watch u trying new methods to achieve the goal.
This man hanged out with liveoverflow during the google ctf..... You're so lucky :)
gamerchunk1 yes. That challenge was badass :) overflow had to defuse a bomb 😇
Or the opposite Liveoverflow being lucky.
@@rabindra1337 I think Liveoverflow knows more stuff. Not saying that is a bad tging or anything
Love this I hope you keep putting the Google ctf solutions out.
Thank you for the videos. You're an excellent teacher. I'm learning so much from you. I agree the way angr found the solution so quickly is some "dark magic". I'm also wondering what practical use cases such a tool might have.
Thanks, I am learning something new each video...
I'm reminded of SoftICE with this back in the day, and thank you for going through the process of obtaining the key - which was arguably the point - but, to save time in practice, I would have just changed the instruction from a JE (Jump Equal), to a JNE (Jump Not Equal), bypassing that branch entirely for every value but the originally-intended one, although that's admittedly not the point, and the process for obtaining the key is extremely informative, so thank you for putting it together. Brute-forcing is of course another approach too.
Thought the same thing, but then I realized they wanted you to know the key and not just skip that block of code ehehe.
wowww!!!!!! bro .. I really learnt a lot with you in this video. you are amazingggg mannn
Wow...! I'm returning to programming after... uhm.... forever being away. This is really cool and helpful to look at what is available for tools, how to use and how to sleuth... impressive!
I think that having you walk though the learning experience is sometimes more beneficial than just a simple guide/walkthrough. It is definitely more in line with how things play out in reality; research and digging into documentation you are no familiar with.
Hi John, i'm searching for a guide of what to use when regarding the sysinternals suite. Thanks for all your work you put in this and beeing a guidepost for the community.
John, your walkthroughs are really good. 🧐
This was super clear! Thanks so much!
Man idgaf if you're reading a writeup you still managed to make the video interesting and we all learned together. I like that you didn't copy and paste. Is a better experience imo than only one of us learning lol. Keep up the good work!
Shoot from the hip my friend. It’s much more encouraging for beginners than breezily solving it with an air of feigned competence 😎
Great video, angr looks really cool!
Great video as always 👍
just got this video recommended, read the name of the channel and thought for almost 10 minutes that if the creator of jurassic park is still alive and has opened a yt channel
loved it! premium stuff! thanks a lot!
Blessings to you John
Thanks! I'm a seasoned dev and never used ltrace thanks I learned something!
Always inspiring 🔥
its really best to learn it this way thanks for this
Great video, great value :)
This was fun! Thank you :)
This was very helpful!
ur a beast i love these videos
I tried as my first challenge in googleCTF as it has least points hours later end up banging my head understanding complicated register play , later reading how people doing with angr automatically solving easily genius man and later more banging my head, i cant solve this 50pts.
Juicy work done...
Great video man. You have plenty of skill yourself so don't need to worry that video will be boring :)
Loved this.
When you said, "Most of em solve this with Angr". I felt that
As a complete, total noob, I'd like to hear you review what you might have done differently after getting a solution. What would you may e have done differently, was there a faster or easier path you could have taken? After the fact did you spot one or more hints or clues or indicators you didn't see until you had the complete picture? What might you have done differently? Please keep these coming!
Really love how these google CTFs writeups are going. It is one thing to watch the videos where the answer is given straight forward but it's another seeing the thought process of John and really going through the steps that i will go through during a CTF and hitting road blocks! Really enjoyed it!
That is the only challange that I have ever solved, both during competition and after it
And personally did it entirely by hand after checking what THREE assembly instructions which ghidra is decompiling as that mess are doing
At least I have learned that x86_64 architecture has some 128 bit registers :D
As a pretty new beginner, this seems a bit tough to solve on my own. Guess I need to familiarize myself better. Good job by the way!
Great video. Thank you. When you said you will use angr I thought you meant anger. lol
So above my head
From the documentation: factory - "It is not a factory in the java sense, it is merely a home for all the functions that produce new instances of important angr classes and should be sitting on Project."
"good, let that angr flow through you"
You can also create the whole flag string with `flag = claripy.BVS('flag', 8*FLAGLEN)` and you can add constraings with `state.add_constraints(f >= ord('!'))` etc...
"unicorn", based on my research, is when you're running on the same architecture and OS as the binary. It's supposed to make the loading faster.
I've just started playing around with angr with crackmes based on these writeups and I've found that it's really hit-or-miss. I can't get it to work with certain strategies. Sometimes an `.explore()` works and sometimes it fails but a `.run()` works which shouldn't be the case...
I tried to do it in the "analyze" way where I tried to reverse the pshufb too.. That sucked. It's difficult for me to understand the ASM instructions especially when they're in the newer instruction sets
Love this. Just so you know , you're pronouncing it Claripy, but it's actually pronounced Claripy. 🤪
Nice Video :) thanks
Nice video. Besides the learning opportunity, what's the benefit of using angr over a regular brute force script in this case?
I'm learning from like 3 of the professors on Shellphish!
POSIX is Portable Operating System Interface.
Just in case anyone was wondering.
Thanks for the video loved the way you explain things . I have a doubt , can't we just decode the string its comparing the input to?😅
I don’t know anything you did - but I loved it. Thank you -
Angr is pretty cool, i like the idea of binary r/e being done with ai.
Liked it!
I have no Idea what is going on,but its awesome!
when I'm researching some techniques in coding, I just use a lot of print()'s and just try and see what it gives, like every couple of new lines and ideas, like when you're trying to explain us what it is putting in "flag" and "flag_chars". Why not just print it ? Then we will directly see what it looks like. I can't grasp why people want to write the whole program first and only see results at the very end.
amazing!
I haven't read what they want. But I would have simply changed the jump address to the Success one. Just like when you crack a program to skip activation (checks).
- they are trying to solve it with anger.
me: ohh, im familiar with that!
- ANGR
- ohh
7:30 : there is a bunch of XOR there. my random guess (ps : you should read the asm code instead of the decompiled C, it would be easier) is that part (or all) of our input is used in the XOR and that would explain why the strcmp in ltrace is invalid garbage
I love reverse enginering videos
is there a place where I can download this CTF?
Hey John, what about Hackthebox BombsLanded reverse engineer CTF? Can you show case it?
more of that please
"i found most people were solving this through anger"
always been the standard process at this house. lol
I can only program in python, I can't understand C, yet I got all the strategy, and I'm starting C just to practice those tests cause I think they would help me increasing my competences, and I think they are a lot of fun
Awesome!
Very nice explanation!
Is anyone facing an issue while running the code on their local machine? For me, when I only allow printable characters, then I am not getting any solution. If comment out those lines, I get garbage values as shown in the video. Please help
I wonder how the flag length was determined that seems like it would be a very important variable. Could always trial and error but maybe find it in ghidra somewhere
If it found "CTF{\x00"... as an output before constraining it, does that mean it would have also been a valid answer (assuming the newline was missing)? I.e. at the command line version, enter: CTF{^D (^D = Press Ctrl-D for EOF). Of course, having to provide it via a webpage breaks that option, since presumable it will always include the newline to input, even though no explicit newline was submitted.
3 years ago hmm good one ❤
See, and I had always been told not to use my anger to solve problems. If only they knew, right? :D
Thanks for the vid! :)