Hello i am arsalan. information system student, i blog about cyber security, ctf writeup , web development , and more about tech. born and raised in indonesia , currently living in indonesia

Posts   About

Writeup CHRIST (Deemed to be University) CTF

this article explains about my writeup.

on 15 to 16 february 2020, i compete on CHRIST (Deemed to be University) CTF organized by secarmy team and got 9th place

N00b_R3v / reversing

100 point | 132 solve

description :

Just Debug It >3
Flag Format ; secarmy{flag}
Author : Elemental X

solution :

flag : secarmy{n00b_rev3rs3r}

Proper Algo / reversing

500 point | 54 solve

description :

So, can you beat my Proper Algo?
You must be good at assembly! :)
nc 178.128.174.25 7331
Author: z0m31en7

solution : there are several function

main :

int __cdecl main(int argc, const char **argv, const char **envp)
{
  int result; // eax
  __int64 v4; // [rsp+8h] [rbp-28h]
  char filename[8]; // [rsp+17h] [rbp-19h]
  FILE *stream; // [rsp+20h] [rbp-10h]
  int v7; // [rsp+28h] [rbp-8h]
  char i; // [rsp+2Fh] [rbp-1h]

  strcpy(filename, "flag.txt");
  puts(&s);
  puts(&byte_2058);
  puts(&byte_20A0);
  puts("\t\t~By z0m31en7\n");
  puts("Enter The License Key:");
  fflush(_bss_start);
  __isoc99_scanf("%lld", &v4);
  v7 = start(v4);
  if ( v7 == 100796628 )
  {
    puts("You are a Worthy one, Here is your flag:");
    stream = fopen(filename, modes);
    if ( !stream )
    {
      puts("Cannot open flag.txt, are you entering the key on the server? ");
      exit(0);
    }
    for ( i = fgetc(stream); i != -1; i = fgetc(stream) )
      putchar(i);
    fclose(stream);
    result = 0;
  }
  else
  {
    puts("WRONG!! you can't beat my Proper Algo ;)");
    result = 0;
  }
  return result;
}

start:

__int64 __fastcall start(__int64 a1)
{
  return (signed int)z(a1);
}

z:

__int64 __fastcall z(__int64 a1)
{
  return (signed int)o(a1 + 290027);
}

o:

__int64 __fastcall o(__int64 a1)
{
  return (signed int)m(a1 + 323302);
}

m:

__int64 __fastcall m(__int64 a1)
{
  return (signed int)b(a1 + 101483);
}

b:

__int64 __fastcall b(__int64 a1)
{
  return (signed int)i(a1 + 201092);
}

i:

__int64 __fastcall i(__int64 a1)
{
  return (signed int)e(a1 + 944);
}

e:

__int64 __fastcall e(__int64 a1)
{
  return (signed int)n(a1 + 59);
}

n:

__int64 __fastcall n(__int64 a1)
{
  return (signed int)t(a1 - 34);
}

t:

signed __int64 __fastcall t(__int64 a1)
{
  return a1 - 27 + 2999;
}

we just need to follow the constraint :

0x60208D4 - 0x46CEB - 323302 - 101483 - 201092 - 944 - 59 - 34 + 27 - 2999 + 68

and send the result

flag : secarmy{pr0p3er_alg05_@re_mu57}

ENCRYPTO X / Miscellaneous

60 point | 70 solve

Description:

One of my friend sent me this binary with two keys "ENCODE" & "DECODE"
and told me the keys are case-sensitive . I am unable to find the hidden
message inside , can you help me out ? :(
Flag Format :- secarmy{flag}

Solution:

this is the pseudo code for main function

int __cdecl main(int argc, const char **argv, const char **envp)
{
  int v3; // eax
  int v4; // eax
  int v5; // eax
  int v6; // eax
  int v7; // eax
  int v8; // eax
  int v9; // eax
  int v10; // eax
  int v11; // eax
  int v12; // eax
  int v13; // eax
  int v14; // eax
  int v15; // eax
  int v16; // eax
  int v17; // eax
  int v18; // eax
  int v19; // eax
  int v20; // eax
  int v21; // eax
  int v22; // eax
  int v23; // eax
  int v24; // eax
  int v25; // eax
  int v26; // eax
  int v27; // eax
  int v28; // eax
  int v29; // eax
  int v30; // eax
  int v31; // eax
  int v32; // eax
  char s1; // [esp+32h] [ebp-96h]
  char v35; // [esp+3Ah] [ebp-8Eh]
  char v36; // [esp+42h] [ebp-86h]
  char v37; // [esp+4Ah] [ebp-7Eh]
  char v38; // [esp+52h] [ebp-76h]
  char v39; // [esp+5Ah] [ebp-6Eh]
  char v40; // [esp+62h] [ebp-66h]
  char v41; // [esp+6Ah] [ebp-5Eh]
  char v42; // [esp+72h] [ebp-56h]
  char v43; // [esp+7Ah] [ebp-4Eh]
  char s2[4]; // [esp+82h] [ebp-46h]
  char v45; // [esp+8Ah] [ebp-3Eh]
  char v46[4]; // [esp+8Bh] [ebp-3Dh]
  char v47; // [esp+93h] [ebp-35h]
  char v48; // [esp+94h] [ebp-34h]
  char v49; // [esp+9Dh] [ebp-2Bh]
  char v50; // [esp+A6h] [ebp-22h]
  char v51; // [esp+A7h] [ebp-21h]
  char v52; // [esp+A8h] [ebp-20h]
  char v53; // [esp+A9h] [ebp-1Fh]
  char v54; // [esp+AAh] [ebp-1Eh]
  char v55; // [esp+ABh] [ebp-1Dh]
  char v56; // [esp+ACh] [ebp-1Ch]
  char v57; // [esp+ADh] [ebp-1Bh]
  char v58; // [esp+AEh] [ebp-1Ah]
  char v59; // [esp+AFh] [ebp-19h]
  char v60; // [esp+B0h] [ebp-18h]
  char v61; // [esp+B1h] [ebp-17h]
  char v62; // [esp+B2h] [ebp-16h]
  char v63; // [esp+B3h] [ebp-15h]
  char v64; // [esp+B4h] [ebp-14h]
  char v65; // [esp+B5h] [ebp-13h]
  char v66; // [esp+B6h] [ebp-12h]
  char v67; // [esp+B7h] [ebp-11h]
  char v68; // [esp+B8h] [ebp-10h]
  char v69; // [esp+B9h] [ebp-Fh]
  char v70; // [esp+BAh] [ebp-Eh]
  char v71; // [esp+BBh] [ebp-Dh]
  unsigned int v72; // [esp+BCh] [ebp-Ch]

  v72 = __readgsdword(0x14u);
  strcpy(s2, "ENCODE");
  v45 = 0;
  strcpy(v46, "DECODE");
  v47 = '\0';
  v60 = 'A';
  v61 = '-';
  v62 = '+';
  v63 = '!';
  v64 = '@';
  v65 = '$';
  v66 = 'b';
  v67 = '4';
  v68 = '0';
  v69 = '9';
  v70 = 'X';
  v71 = 'D';
  v50 = 'e';
  v51 = 'n';
  v52 = 'c';
  v53 = 'o';
  v54 = 'd';
  v55 = 'e';
  v56 = 'b';
  v57 = 'i';
  v58 = 't';
  v59 = 's';
  v3 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want  : ");
  std::ostream::operator<<(v3, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &s1);
  if ( !strcmp(&s1, s2) )
    v4 = std::operator<<<std::char_traits<char>>(&std::cout, v50);
  else
    v4 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v4, &std::endl<char,std::char_traits<char>>);
  v5 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want : ");
  std::ostream::operator<<(v5, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v35);
  if ( !strcmp(&v35, v46) )
  {
    v6 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v6, &std::endl<char,std::char_traits<char>>);
  }
  else
  {
    v7 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v7, &std::endl<char,std::char_traits<char>>);
  }
  v8 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v8, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v36);
  if ( !strcmp(&v36, s2) )
    v9 = std::operator<<<std::char_traits<char>>(&std::cout, v51);
  else
    v9 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v9, &std::endl<char,std::char_traits<char>>);
  v10 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v10, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v37);
  if ( !strcmp(&v37, v46) )
  {
    v11 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v11, &std::endl<char,std::char_traits<char>>);
  }
  else
  {
    v12 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v12, &std::endl<char,std::char_traits<char>>);
  }
  v13 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v13, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v38);
  if ( !strcmp(&v38, s2) )
    v14 = std::operator<<<std::char_traits<char>>(&std::cout, v52);
  else
    v14 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v14, &std::endl<char,std::char_traits<char>>);
  v15 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want : ");
  std::ostream::operator<<(v15, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v39);
  if ( !strcmp(&v39, v46) )
  {
    v16 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v16, &std::endl<char,std::char_traits<char>>);
  }
  else
  {
    v17 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v17, &std::endl<char,std::char_traits<char>>);
  }
  v18 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v18, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v40);
  if ( !strcmp(&v40, s2) )
    v19 = std::operator<<<std::char_traits<char>>(&std::cout, v53);
  else
    v19 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v19, &std::endl<char,std::char_traits<char>>);
  v20 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v20, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v41);
  if ( !strcmp(&v41, v46) )
    v21 = std::operator<<<std::char_traits<char>>(&std::cout, v54);
  else
    v21 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v21, &std::endl<char,std::char_traits<char>>);
  v22 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v22, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v42);
  if ( !strcmp(&v42, s2) )
  {
    v23 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v23, &std::endl<char,std::char_traits<char>>);
  }
  else
  {
    v24 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v24, &std::endl<char,std::char_traits<char>>);
  }
  v25 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v25, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v43);
  if ( !strcmp(&v43, v46) )
    v26 = std::operator<<<std::char_traits<char>>(&std::cout, v55);
  else
    v26 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v26, &std::endl<char,std::char_traits<char>>);
  v27 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v27, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v48);
  if ( !strcmp(&v48, s2) )
  {
    v28 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v28, &std::endl<char,std::char_traits<char>>);
  }
  else
  {
    v29 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
    std::ostream::operator<<(v29, &std::endl<char,std::char_traits<char>>);
  }
  v30 = std::operator<<<std::char_traits<char>>(&std::cout, "What do you want :");
  std::ostream::operator<<(v30, &std::endl<char,std::char_traits<char>>);
  std::operator>><char,std::char_traits<char>>(&edata, &v49);
  if ( !strcmp(&v49, s2) )
    v31 = std::operator<<<std::char_traits<char>>(&std::cout, v56);
  else
    v31 = std::operator<<<std::char_traits<char>>(&std::cout, &v60);
  std::ostream::operator<<(v31, &std::endl<char,std::char_traits<char>>);
  v32 = std::operator<<<std::char_traits<char>>(&std::cout, "its");
  std::ostream::operator<<(v32, &std::endl<char,std::char_traits<char>>);
  return 0;
}

flag : secarmy{encodebits}

Dumpster Diving / Miscellaneous

100 point | 65 solve

Description :

Always follow the format , if you understand the format,
the flag is all yours , beware of fake flags.
To know more about it :- https://searchsecurity.techtarget.com/definition/dumpster-diving
Flag Format :- secarmy{flag}

Solution : decode all gibber.txt

key : 1010111113

flag : secarmy{5656575656259}

Multiple Ways / Miscellaneous

200 point | 41 solve

Description :

I love various encoding schema like Enigma and what not ,
also I feel encoding my keys are safe . Can you crack them ?
Flag Format :- secarmy{flag}

Solution :

Open binary on ida , take a look on realflag() function

__int64 realflag(void)
{
  __int64 v0; // rax
  __int64 v1; // rax
  const char *v2; // rsi
  __int64 v3; // rax
  __int64 v4; // rax
  char s1; // [rsp+0h] [rbp-80h]
  char s2[8]; // [rsp+15h] [rbp-6Bh]
  __int64 v8; // [rsp+20h] [rbp-60h]
  __int64 v9; // [rsp+28h] [rbp-58h]
  int v10; // [rsp+30h] [rbp-50h]
  char v11; // [rsp+34h] [rbp-4Ch]
  char v12; // [rsp+40h] [rbp-40h]
  char v13; // [rsp+6Bh] [rbp-15h]
  int v14; // [rsp+6Ch] [rbp-14h]

  std::allocator<char>::allocator(&v13);
  std::__cxx11::basic_string<char,std::char_traits<char>,std::allocator<char>>::basic_string(&v12, "0xbbbbbbbbb", &v13);
  std::allocator<char>::~allocator(&v13);
  v8 = 'fymraces'; // <---- this is the flag
  v9 = '@cyllani'; // <---- this is the flag
  v10 = 'rutp'; // <---- this is the flag
  v11 = 51; // <---- this is the flag
  strcpy(s2, "SECARMYCTF");
  std::operator<<<std::char_traits<char>>(&std::cout, "Enter your key :");
  std::operator>><char,std::char_traits<char>>(&std::cin, &s1);
  v14 = strcmp(&s1, s2);
  if ( v14 )
  {
    v3 = std::operator<<<std::char_traits<char>>(&std::cout, "Fooled");
    v4 = std::operator<<<char,std::char_traits<char>,std::allocator<char>>(v3, &v12);
    std::ostream::operator<<(v4, &std::endl<char,std::char_traits<char>>);
    v2 = "Not Pwned!";
    std::operator<<<std::char_traits<char>>(&std::cout, "Not Pwned!");
  }
  else
  {
    v0 = std::operator<<<std::char_traits<char>>(&std::cout, "Here is your flag: ");
    v1 = std::operator<<<std::char_traits<char>>(v0, &v8);
    v2 = (const char *)&std::endl<char,std::char_traits<char>>;
    std::ostream::operator<<(v1, &std::endl<char,std::char_traits<char>>);
  }
  return std::__cxx11::basic_string<char,std::char_traits<char>,std::allocator<char>>::~basic_string(&v12, v2);
}

flag : secarmy{finallyc@ptur3}

CrackOut / Miscellaneous

200 point | 33 solve

Description :

Check out each & every letter :) , key itself is the flag
Flag Format:- secarmy{flag}

Solution :

i made a script to brute wearesecarmy.zip

import zipfile


def main():
	"""
	Zipfile password cracker using a brute-force dictionary attack
	"""
	zipfilename = 'wearesecarmy.zip'
	dictionary = 'word'

	password = None
	zip_file = zipfile.ZipFile(zipfilename)
	with open(dictionary, 'r') as f:
		for line in f.readlines():
			password = line.strip('\n')
			try:
				zip_file.extractall(pwd=password)
				password = 'Password found: %s' % password
			except:
				pass
	print password

if __name__ == '__main__':
	main()

and use pass.txt as the wordlist

curabitur
vitae
nunc
sed
...
...
...
...
sed
arcu
vestibulumi

flag : secarmy{vestibulumi}

UnderTheMines / Miscellaneous

500 point | 97 solve

Description :

Howdy Pirate!! Ready For Some OldSchool Fun?
Here It is: nc 178.128.174.25 2341

Solution :

this is just minesweeper , just play the game

Current Status of Board :
    0 1 2 3 4 5 6 7 8

0   1 - 3 - 4 - - 1 0
1   1 1 3 - - - 3 1 0
2   0 0 1 1 2 1 1 0 0
3   1 1 0 0 0 0 0 1 1
4   - 1 1 1 1 0 0 1 -
5   1 1 1 - 1 0 0 1 1
6   0 0 1 1 1 0 0 0 0
7   0 0 0 0 0 0 0 0 0
8   0 0 0 0 0 0 0 0 0
Enter your move, (row[space]column) -> 1
4

You Won Pirate!! here, take the flag: secarmy{th3_cl@551c_m1n3sw33per}

flag : secarmy{th3_cl@551c_m1n3sw33per}

E-Digger / OSINT

200 point | 82 solve

Description :

Hey there , our team member just found his new domain name
but I am not sure if I should email through it . Please check out .
http://umairnehri.me/
Flag Format :- secarmy {flag}

Solution :

i use https://dnschecker.org/ to get the flag

flag : secarmy{$pf_r3c0rd$_@1n7_b0r1ng_r1gh7?}

The Customer / Web

100 point | 61 solve

Description :

Hey, I just joined a cookie store but I think I won't be able
to perform the job which had been ordered by my manager.
Please help me out!
https://labs.sec.army/customer/

Solution :

i use curl command to set order cookie

curl --header "Cookie: order=100" https://labs.sec.army/customer/

flag : secarmy{h3r3s_s0m3_fr33_c00k13s_f0r_y0u}

The Classic User Panel / Web

100 point | 25 solve

Description :

Hey looks like the User Panel of my store is pretty
outdated and is sort of vulnerable.Go have some fun out there ;)
https://labs.sec.army/userpanel/

Solution : just trigger xss with hi

<script>alert('hi')</script>

flag : secarmy{l0ng_l1v3_7h3_cr0ss_s173_scr1p71ng}

SNOW / Stegnography

100 point | 174 solve

Description :

Snow & Snow everywhere , can you help me to find the flag ?
Flag Format :- secarmy{flag}

Solution :

just run command

./snow/snow -C Snow\ Is\ EveryWhere.txt
echo "c2VjYXJteXtDbGVhcl9UaGVfU25vd30=" | base64 -d

flag : secarmy{Clear_The_Snow}

B1n_Bas1c / Starters

10 point | 457 solve

Description :

Welcome to the battlefield warrior ! More power to you ;)
Flag Format :- secarmy{flag}

Solution :

just convert , bin to string. i use https://codebeautify.org/binary-string-converter

flag : secarmy{b1nary_is_c00l}

Go Emojis / Starters

20 point | 215 solve

Description :

Here's official server of SECARMY let's see if you can find the flag :)
Server Link : https://discord.gg/AMvR2WW

Solution :

just take a look on Go emoji

flag : secarmy{g0_ln_hs_the_flag}

Welcome / Starters

30 point | 112 solve

Description :

Welcome on the board ! Know about us and get your flag
Flag Format : secarmy{flag}

Solution :

flag on http://178.128.174.25/about

flag : secarmy{All_H@1L_CHR1ST}

DecodeM3 / Forensics

100 point | 111 solve

Description :

Enjoy the audio and hunt for the flag ! Fun hearing >3.
Flag Format :- secarmy{flag}

Solution : i use this website : https://morsecode.world/international/decoder/audio-decoder-adaptive.html

flag : secarmy{M0RSEDEC0DED}

Dive Deep ! / Forensics

500 point | 3 solve

Description :

Are you good at forensics? can we test you ?
Dive in :- https://drive.google.com/file/d/1gVnPf5axFovFcl-arFZu39dE-qsDmR5s/view?usp=sharing
extract the real flag, its easy.
Flag Format : secarmy{}

Solution :

import .ova file to virtualbox , and set MAC Address Policy : Generate new MAC addresses fro all network adapters

Reset password using grub , press e

and set the configuration like this

and you will get root

don’t forget to reset root password , and restart

now i use testdisk command

testdisk /dev/sda

and select

and select analyse

choose c to copy file to working directory

go to root , and install apache2 webserver and ngrok for port forwarding

after that , just download the file using ngrok url. now we have to crack Flag.zip , i use fcrackzip to crack it

we need to fix the signature file

i use hexeditor

now we got

i use steghide to extract the real flag , with password -blank-

now we have to crack flag.zip using fcrackzip

just unzip flag.zip using 123456 as the password and we get the flag

flag : secarmy{th4t_w4$_3asy}

SEC++ / Programming

90 point | 169 solve

Description :

Oi! h0p3 y0u $t1ll r3m3mb3r C++! d0n't y@ ? ;)
Author : Umair9747
SECARMY{cpp_1s_TH3_W@Y_T0_G0}
Flag format :- secarmy{flag}

Solution : we are given a C++ source code

class sec{
    public:
    void army(char b[40]){
        for(int i=0;i<strlen(b);i++){
            if(isupper(b[i])){
                b[i]=tolower(b[i]);
            }
            if(islower(b[i])){
                b[i]=toupper(b[i]);
                b[9]='$';
            }
            if(isdigit(b[i])){
                b[i]='%';
            }
            if(b[i]=='%'){
                b[i]=b[i-1];
                b[24-1]='0';
                if(isupper(b[i])){
                    b[i]=b[i-1];
                }
            }
        }
        for(int i=0;i<strlen(b);i++){
              if(isupper(b[i])){
                   b[i]=tolower(b[i]);
              }
              b[13]='e';
              if(b[i]=='t'){
                  b[i]=tolower(b[i]);
              }
              if(b[i]=='s'){
                  b[i-1]=b[i];
              }
              if(b[i]=='p'){
                  b[i]=b[11];
              }
              if(b[i]=='T'){
                  b[i]='+';
              }
              b[8]='1';
        }
                      b[11]='7';
        std::cout<<b;
}
};

just fix a little bit

#include <iostream>
#include <cstring>

class sec{
    public:
    void army(char b[40]){
        for(int i=0;i<strlen(b);i++){
            if(isupper(b[i])){
                b[i]=tolower(b[i]);
            }
            if(islower(b[i])){
                b[i]=toupper(b[i]);
                b[9]='$';
            }
            if(isdigit(b[i])){
                b[i]='%';
            }
            if(b[i]=='%'){
                b[i]=b[i-1];
                b[24-1]='0';
                if(isupper(b[i])){
                    b[i]=b[i-1];
                }
            }
        }
        for(int i=0;i<strlen(b);i++){
              if(isupper(b[i])){
                   b[i]=tolower(b[i]);
              }
              b[13]='e';
              if(b[i]=='t'){
                  b[i]=tolower(b[i]);
              }
              if(b[i]=='s'){
                  b[i-1]=b[i];
              }
              if(b[i]=='p'){
                  b[i]=b[11];
              }
              if(b[i]=='T'){
                  b[i]='+';
              }
              b[8]='1';
        }
                      b[11]='7';
        std::cout<<b;
}
};


int main(){
  char x[40] = "SECARMY{cpp_1s_TH3_W@Y_T0_G0}";
  sec o;
  o.army(x);

}

compile and run it

flag : secarmy{1$_7_e_thh_w@y_00_gg}

Power it Up ! / Programming

100 point | 94 solve

Description :

It's a headache to debug this piece of Powershell script .
Help me out to find the output & the flag is all yours ;)
Flag Format :- secarmy{flag}

Solution :

we got challenge.txt

$a = "Null"
$b = "0x00"
$c = "0x00" -in $a
$d = "null" -ge $b
$e = ($d -eq $c) -or ($a -eq $b)
$f = ($d -eq $c) -xor ($a -eq $b)
if(($d -eq $c) -or ($a -eq $b)) {$e} else {$f}

i use this website https://tio.run/#powershell , just compile it and got the flag

flag : secarmy{false}

SUM_IT_UP / Crypto

70 point | 67 solve

Description :

My newbie scripting friend just got fooled by one of his friend and the message has been hidden using Powershell , if you help him to understand, I hope he will provide you the flag.
Warning: You might be fooled !
Flag Format:- secarmy{flag}

Solution :

we are given flag.txt

if(D642C>JL#__E6? -eq pvcure) {"flag"}

i use https://cryptii.com/pipes/caesar-cipher to decode it.

and the last part

flag : secarmy{R00tencipher}

Nothingness / Crypto

100 point | 11 solve

Description :

Life is although void , but SECARMY can help you out , hope you get it >3.
Flag Format:- secarmy{flag}

Solution :

i use this website https://cryptii.com/pipes/nihilist-cipher set separator to and set SECARMY as the key

flag : secarmy{thekeytopoints}

Unit3d_C0d3 / Crypto

100 point | 125 solve

Description :

We unite to code .
Flag Format:- secarmy{flag}

Solution :

we are given flag.txt

&#x73; &#x65; &#x63; &#x61; &#x72;
&#x6d; &#x79; &#x7b; &#x49; &#x5f;
&#x6c; &#x30; &#x76; &#x65; &#x5f;
&#x55; &#x6e; &#x69; &#x63; &#x30;
&#x64; &#x65; &#x0; &#x7d;

i use this website https://www.url-encode-decode.com/

flag : secarmy{I_l0ve_Unic0de}

Old School / Crypto

100 point | 242 solve

Description :

Hope the name is enough for you
Flag Format :- secarmy{flag}

Solution :

we are given a file ct.txt

01001101 01010100 01000001 01110111 01001001 01000100 01000101 01111000 01001101 01010011 01000001 01111000 01001101 01010100 01100011 01100111 01001111 01010100 01100111 01100111 01001101 01010100 01000001 00110100 01001001 01000100 01000101 01110111 01001101 01010011 01000001 00110101 01001110 01111001 01000001 01111000 01001101 01000100 01100111 01100111 01001101 01010100 01000001 01111010 01001001 01000100 01000101 01111000 01001101 01010011 01000001 01111000 01001101 01010100 01010001 01100111 01001101 01010100 01000001 00110001 01001001 01000100 01000101 01111000 01001110 01101001 01000001 01111000 01001101 01000100 01010001 01100111 01001101 01010100 01000001 00110101 01001001 01000100 01000101 01111000 01001110 01010001 00111101 00111101

just convert it to string and we will get

and decode the result with base64

and decode again with decimal

flag : secarmy{doublealgorithms}

Goodbye / Goodbye

10 point | 50 solve

Description :

Hope you enjoyed it >3.
Do not forget to provide us a valuable feedback
https://forms.gle/gUNpXfvfstiwM3269
Goodbye !

Solution :

just fill the form and you will get the flag

Introduction / Welcome

2 point | 447 sove

Description :

We know you all are the smartest & sweetest beings of the universe , Do not hesitate to introduce yourself >3.
. https://forms.gle/Vy9A2pyaAbWrXuae6

Solution :

just fill the form and you will get the flag