[Tutorial] OllyDBG - The very basics

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Originally Posted by Silent-Death nice.. this is the stuff epvp is for. Great work!

Thanks :) And yeah, I agree. Hopefully I can find the time to put up some more stuff like this to prod others into doing the same.

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Originally Posted by Zeroxelli o.O did I? Where'd I post it? I think browsing forums after using the "preview" function resets the sub-forum number.

It was in pserver releases and from the look of it; it's a general olly tutorial.

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Originally Posted by Kiyono It was in pserver releases and from the look of it; it's a general olly tutorial.

Yeah, that was my fault then. Sorry about that.


Also, added 3 more "Crack Me" applications for you guys to mess with.

Edit 2: Added a quick video on solving "Crack Me"s 3, 4, and 5. Check the bottom of the post.

I think the effort put into this is awesome, but in my opinion it's missing the actual basics.
What a debugger actually does, what the stack is for, what registers do, why people use trace, what the basic assembly opcodes are.
I mean I don't want to sound like I'm talking this thread down or anything, I mean I think the effort is awesome. But this is more a tutorial on how to 'crack' your CrackMe's then an explanation about the basics of OllyDbg. But that's just my point of view!

Anyway nice thread you'll get a thank you for the effort ! :)

Yeah, it's a tutorial on OllyDBG, not understanding the ASM. If I were to go into explaining what the stack is, the stack vs. the heap, how registers work, etc, it'd probably be 5x as long. I was trying to go on the assumption that people would have a slight amount of knowledge of the way things worked. When I first learned coding I started with PHP, and because PHP's interpreter was/is coded in C, I looked up C. Of course, I found out that C goes down even lower to ASM, so I went and looked up ASM, which lead me to mess around with it a bit, so I learned some of the operation codes early on.

While I do feel it's necessary for them to know these things, I've said before that I'm not going to give everything to them. At least not at once. If I give 120%, I want you to give at least 60% of the absolute value of that 120%. Half in, half earned. ;)

I may make a thread the basics of ASM (including the use of the register, etc.), we'll see.

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Originally Posted by Zeroxelli Yeah, it's a tutorial on OllyDBG, not understanding the ASM. If I were to go into explaining what the stack is, the stack vs. the heap, how registers work, etc, it'd probably be 5x as long. I was trying to go on the assumption that people would have a slight amount of knowledge of the way things worked. When I first learned coding I started with PHP, and because PHP's interpreter was/is coded in C, I looked up C. Of course, I found out that C goes down even lower to ASM, so I went and looked up ASM, which lead me to mess around with it a bit, so I learned some of the operation codes early on. While I do feel it's necessary for them to know these things, I've said before that I'm not going to give everything to them. At least not at once. If I give 120%, I want you to give at least 60% of the absolute value of that 120%. Half in, half earned. ;) I may make a thread the basics of ASM (including the use of the register, etc.), we'll see.

Glad you take my feedback positively, rare these days haha.
Anyway yes I understand you're not going too much in dept, that's logical but if you write a topic name as this "Ollydbg - The very basics" the things you just mentioned are part of debugging in general, everyone can apply a jump or a nop when told, not everyone understands of the bat why they should.

It's kind of just asking for all the "noob" questions because they simply don't know why they are doing what, I'm not saying you should write all that down either but maybe some links to for example what the registers stand for accumulator, base, counter, destination, source etc.. You know so they get a more complete overview to begin with, would be a great addition to this thread. Like I said nothing wrong with the thread, I like to see stuff like these so the community can grow and learn but I don't think the right way to learn is to follow how someone exactly does something ;)

And I totally agree on if you give your best you have expectations back, that they do their research and I fully agree on that, anyone that's truly interested in RE will do his research none the less. There is just so much more to RE and so many different ways into achieving the same things, way too much to explain in dept, but anyone that starts with this should know how to debug, how functions are made up, how loops look like, why the registers are used. The system wide modules and what they do, it's a lot to grasp at first I can imagine :)

Well, that's actually the reason why the thread is for OllyDBG and not RE/Debugging in general. I wasn't intending to preschool them step-by-step through understanding how it works and what everything means. As much as people would like to be spoon fed, I don't believe in handing them the answer to run with. It's like a mouse in a maze: you've already given him the cheese, he just has to use his skill and effort to make his way through the bends and get the goal (in his case, the cheese. In theirs, the answer/skills/etc.)

As I said, I'll probably write up something for them in the near future. Working 6-8 hours a day, taking care of grandmother, working on the house/revamping the yard, traveling in and out of the city, etc. Not to mention paying attention to the wife so I don't get yelled at :) It takes up a lot of my time, but all my free time goes to this community. That, I can promise.

Thanks very much , it contains alot of usefull information :)

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Originally Posted by dungzkii nice tutorial :)

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Originally Posted by ah_mmed Thanks very much , it contains alot of usefull information :)

No problem, glad you found it useful.

is there a downside to not having cygwin? because apparently i need a bunch of dll's from it in order to open the crackme's

I get an error message of program can not start becuase cgywin1.dll is missing from your computer when i try to open crackme01 with olly...

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Originally Posted by koseta I get an error message of program can not start becuase cgywin1.dll is missing from your computer when i try to open crackme01 with olly...

Well I wonder why it says cgywin1.dll. Perhaps, the file is missing.

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Originally Posted by koseta I get an error message of program can not start becuase cgywin1.dll is missing from your computer when i try to open crackme01 with olly...

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