Hello, This challenge is not that hard but it’s quite confusing. To solve this challenge very quickly all you have to do is patch it in 2 places and then run it with different arguments until the flags get’s spiten out. Here’s a sample script that runs the binary 100 times with arguments from 1 to 100 [code language=”bash”] printf ‘start\n’ for i in {1..100} do printf “$i ” ./program “$i” | xxd -r -p printf ‘\n’ done printf ‘\nend\n’ [/code] ...
Hello, If you open this binary in Binary Ninja or any other disassembler, you’ll see a that the flow is quite weird. After looking at the strings tab I found UPX listed in there, this explains the weird graph. UPX is an open-source packer. A packer is just a piece of software that compresses the binary, when the binary is run it will unpack itself. Packing an exe could reduce it’s size by 30% or so.. since UPX is free you could also use it to unpack binaries. Unpacking is left as a exercise to the reader (I’m lazy) ...
Hello, this is a write-up regarding the HackTheBox reversing challenge: Impossible Password. Please don’t look at the solution if you haven’t attempted the challenge yet, it will ruin all the fun. Try to solve the challenge by yourself first, just put some hours into it, it isn’t that hard. I’m also a newbie at RE. Here are some hints to get you started: The function call convention of this program seems to be: System V AMD64 ABI. Debug the program in a debugger like: edb-debugger. Okay, so, let’s solve this. ...