DarkCTF 2020: Rev/strings
Sept. 27, 2020 in CTF, CTF writeups
Rev/strings
363 points
Description:Just manipulation of couple of strings....
Note: Enclose the final output inside darkCTF{} File
Solution
I used the ghidra to do the initial analysis. Looks like binary takes the input (do nothing with it;)), then calculate some string (I assumed it's a flag) and exit.
Let's try to debug...
gdb ./strings
break _exit
run
Then dumped the memory before program exit.
Ok, let’s examine the memory dump…
Oh?! What’s that? Is it a flag? Bingo! ;-)
darkCTF{wah_howdu_found_me}