Tag: reverse

Leet More 2010 SHAdow dROP writeup

Category: reverse Generate a license! shadowdrop.exe Lets start with examining the binary. It installs a SEH handler with “bad guy” message, pushes some binary trash on the stack, opens “license.key“, and for each 5 bytes in reads from license, it calculates their SHA-1 and xors another 20 bytes on stack with hash binary. After xoring …

Continue reading

Leet More 2010 Stack or what? writeup

We received a new CPU model, you are to make a vulnerability check. Enter the CPU secret code as a proof. [ ctf.ifmo.ru:3123 ] + binary Here we have a VM with a few instuctions: nop, add, xor, mul, push, pop, loop, pops, pushs and core. The most intresting is core – it spawns a …

Continue reading