[Reversing] Bypass

I create the post to collect all the ideas about the challenge. obviously without giving spoilers

Pretty cool challenge, learned some new tricks. What I did wasn’t reversing per se, but it should be possible.

Nice challenge. I used a disassembler and some breakpoints to get the flag… But i don’t undestand how i could get the flag with static analysis. Someone could pm me?

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

This was a very simple challenge and basic practice for newcomers in re. i quite like this, kudos Baikuya!

Type your comment> @Baikuya said:

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

That’s a huge spoiler in itself

Type your comment> @unsux said:

This was a very simple challenge and basic practice for newcomers in re. i quite like this, kudos Baikuya!

Thank you very much

@dosxuz said:
Type your comment> @Baikuya said:

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

That’s a huge spoiler in itself

Well I dont think so. If you read the challange description you can see that you must bypass something…

It took me longer to clone and build dnSpy than to do the bypass ?.
Great tool!! Thanks

First time using dnSPY. I had difficulties recompiling the code but found a work around. Overall cool simple challenge. PM for nudge

This challenge was really fun for a complete noob like me. Thanks @Baikuya!

Your welcome :slight_smile:

Cool challenge, I first tried the other spy, but the obfuscation was “unbreakable” :-). Learned something new.

Type your comment> @Baikuya said:

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

I did in fact complete the challenge via static analysis. I’ll PM you.

This was fun. I didn’t know much about .NET and reversing it, nor did I know much about the tools to do it, so this was a very nice way to get to know them both.

If anyone could PM me and help me with this I’d much appreciate it. This is my first time reversing and I can understand the code, but I can’t seem to figure out certain components.

Type your comment> @pythonier5001 said:

If anyone could PM me and help me with this I’d much appreciate it. This is my first time reversing and I can understand the code, but I can’t seem to figure out certain components.

I really need the help as well.

EDIT: Actually this was easy, and very nice. This was my first RE challenge. Feel free to DM me if you need help.

I’m a very beginner in CTFs so I’m with some difficulty to solve it. I was trying to hack the .exe file through radare2, but it was so difficult. So I read here that you guys were using something like dnSpy, but I’m in Linux and I can’t install it. Is there some tool similar to dnSpy to Linux? I saw on the internet a guy that solved this problem using OllyDbg as well, but I’m trying to use it with wine and when I run the Bypass.exe OllyDbg crash. An alternative to OllyDbg in Linux is the edb-debugger, but when the program print “Enter a username:” edb-debugger crash too.

Its easy with basic reverse and basic logic

Type your comment> @Baikuya said:

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

@Baikuya why create a challenge that requires a specific tool to solve? Just curious. I am using IDA disassembler to solve it and it’s not working. It says processor ‘cli’ is not included. So I have to install and use a tool like Dnspy. This is why I am curious.

Type your comment> @Baikuya said:

If someone finds a way to get the flag with static analysis PM me.
I created the Challange and it was meant to use a Debuger like Dnspy :slight_smile:

I use kali linux and I am running dnSpy with wine. In dnSpy, I am getting an error:

Error: Couldn't find the CLR dll file

Can you help?