1. Reversing an Executable
Ones and Zeros are hard to read, right?
(… Actually, yes)

2. What even is a Binary?
Technically, it’s a bunch of bits (ones and zeros)
BUT EVERYTHING ON COMPUTERS IS BINARY?!?!1!ONE?!?
For us: a compiled program.

3. Disassembly? Machine language
Tools: radare2, GDB, IDApro (super fancy)
I am not an expert with these tools.

4. Wait, there has to be an Easier way…
Strings!
Strings <filename> will print out all strings in the passed file.
Can use on binaries too!
Hardcoded passwords == BAD
This is a good starting point

5. Reverse Engineering a Binary
Analyzing machine language to interpret what the program does.
Commands for radare2:
r2 <Executable name>
aa – Analyze all symbols
afl – List all functions
<function name> - Print Disassembled Function

6. Commands: Continued Useful gdb commands:
gdb <executable> - Opens gdb on the specified file.
break <function name/ *address> - sets a breakpoint
info registers – displays the contents of the registers
set $addr val – sets the value at $addr to val
disassemble <function name>
For more fun things, see instructions.txt!

7. Can you Solve ‘em? Go to our Dawgden page. Go to Documents
Intro_To_Reversing
c1.txt and c2.txt are both binary executables. Try breaking them!
Hint for c1: It’s a good starting point
Hint for c2: You don’t even need to guess a password. . .