App Challenge Tips
App Challenge Tips
I solved all the app challenges on the site using only 3 programs: a hex editor, OllyDbg, and asvdemo. I also used a lot of paper.
Basically if you want to change the way an app looks, use a hex editor. Otherwise you'll need Olly.
For the apps that you need the hex editor, find what you need to change, and then change it. It's usually something not too difficult (i.e. making two string match).
The apps that need Olly usually take a bit more time. Make sure to look for text string (ASCII and unicode). I like to use a lot of breakpoints and try to figure out what's going on. The key is to find that critical comparasion. Somewhere in the code there has to be a comparasion between the input and the key. Find that comparasion, and work backwards.
If you want any more tips or specific help PM me.