Tags: reverse engineering bin string 

Rating:


---- Writeup ----
CTF: BACKDOOR 2014
Problem: binary-10
Author: Dr.Optix
All rights reserved.
-----------------

I will start with basic recon.

$ file bin10
bin10: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically
linked (uses shared libs), for GNU/Linux 2.6.24, BuildID
[sha1]=e0f10986e9a0fc976ff2be10b411f368bfd53700, not stripped

$ strings bin10
/lib64/ld-linux-x86-64.so.2
CyIk
libstdc++.so.6
__gmon_start__
_Jv_RegisterClasses
pthread_cancel
_ZNSsD1Ev
_ZNSt8ios_base4InitD1Ev
_ZNSsC1EPKcRKSaIcE
_ZNKSs7compareEPKc
_ZNSaIcEC1Ev
_ZSt3cin
_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RSbIS4_S5_T1_E
__gxx_personality_v0
_ZSt4cout
_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc
_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_
_ZNSaIcED1Ev
_ZNSsC1Ev
_ZNSolsEPFRSoS_E
_ZStlsIcSt11char_traitsIcESaIcEERSt13basic_ostreamIT_T0_ES7_RKSbIS4_S5_T1_E
_ZNSt8ios_base4InitC1Ev
libgcc_s.so.1
_Unwind_Resume
libc.so.6
__cxa_atexit
__libc_start_main
GCC_3.0
GLIBC_2.2.5
CXXABI_1.3
GLIBCXX_3.4
fff.
l$ L
t$(L
|$0H
40511702a6193f9b38d37699e676fd40
Enter the password:
a_few_basic_skills_will_do
The flag for this level is
That doesn't seem to be the correct password.
Access Denied.
;*3$"
zPLR


This looks like a potential flag: 40511702a6193f9b38d37699e676fd40

Bingo! Flag is indeed: 40511702a6193f9b38d37699e676fd40

~ Q.E.D