China DOS Union

First, change the form a little:

@echo off&setlocal enabledelayedexpansion

set code=a b c d e f g h i j k l m n o p q r s t u v w x y z

set "zw=for %%i in (%code%) do "&set "wz=set "&set "ww=call :zh"

%ww%

!_5!!_3!!_8!!_15! !_2!!_2!!_19!.!_2!!_1!!_20!!_8!!_15!!_13!.!_3!!_14!

!_16!!_1!!_21!!_19!!_5!

:zh

%zw%(%wz%/a n+=1&%wz%_!n!=%%i)

Expert!!!!

Using variables in place of commands
Clever... but just export the variable table...

Originally posted by knoppix7 at 2008-6-22 21:14:
Using variables in place of commands
Clever... but just export the variable table...

Add password verification too (after entering it, it won't report an error, but if it's wrong it just won't run), and for now don't change the letter order:

@echo off&setlocal enabledelayedexpansion

set /p code=Please enter the run password:

set "zw=for %%i in (%code%) do "&set "wz=set "&set "ww=call :zh"

%ww%

!_5!!_3!!_8!!_15! !_2!!_2!!_19!.!_2!!_1!!_20!!_8!!_15!!_13!.!_3!!_14!

!_16!!_1!!_21!!_19!!_5!

:zh

%zw%(%wz%/a n+=1&%wz%_!n!=%%i)

This way even if the variables are exported, without knowing the password it still won't work, hehe.

[ Last edited by zw19750516 on 2008-6-22 at 09:36 PM ]

a b c z e q q h...
The password isn't absolute... Spend a little time and you can come up with several passwords~

If a wrong password happens to get combined into commands like del or rd, that'd be depressing, hehe.

Feels like this thread is good for helping newbies understand what variable expansion is~

Originally posted by HAT at 2008-6-22 22:35:
If a wrong password happens to get combined into commands like del or rd, that'd be depressing, hehe.

Haha, yes, looking at it this way, even brute-force cracking won't do.

Originally posted by pusofalse at 2008-6-22 22:30:
a b c z e q q h...
The password isn't absolute... Spend a little time and you can come up with several passwords~

What if my password were like this: a 0 z # c 4 + q - ....................x @. Then I think the password would definitely be absolute, and basically impossible to solve. Hehe, I thought of this idea today while lying on the bed. It should count as original; at least nobody on cn-dos has brought it up before.

Looking at the senior member's code, the letter z isn't used, so z can be removed...
a b c are all present, so the first three letters have to be a b c
d isn't used either, so the fourth position can be any letter, number, or Chinese character~
e has to be in the fifth position... and so on...
From this we can infer it...

[ Last edited by pusofalse on 2008-6-22 at 11:34 PM ]

a b c CN e  dos batch h encryption 处 理 室 m n o p 。 加 s t u 密 新 思 路 .

If each position can only be changed once, then there can be 19 passwords...
If it can be changed multiple times, then there can be countless passwords~
You just have to make sure of the positions...

[ Last edited by pusofalse on 2008-6-23 at 12:30 AM ]

Originally posted by pusofalse at 2008-6-23 00:13:

a b c CN e  dos batch h encryption 处 理 室 m n o p 。 加 s t u 密 新 思 路 .

If each position can only be changed once, then there can be 14 passwords...
If it can be changed multiple times, there can ...

Come on, I can scramble the order and add useless characters into the password, then modify the batch file myself according to the password — that's my idea. For example: when password code is b a c........, then every a in the batch file is written as !_2!; when password code is ..........................s g a(the 30th position), then every a in the batch file is written as !_30!

Originally posted by zw19750516 at 2008-6-23 12:27 AM:

Come on, I can scramble the order and add useless characters into the password, then modify the batch file myself according to the password — that's my idea. For example: when password code is b a c........, then every a in the batch file is written as ...

Oh~ so that's how it is, you still have to modify the batch file too?~ In that case it really would be hard to crack... what if you forget it yourself, ^_^

Originally posted by pusofalse at 2008-6-23 00:37:


Oh~ so that's how it is, you still have to modify the batch file too?~ In that case it really would be hard to crack... what if you forget it yourself, ^_^

Just write yourself a ciphertext comparison table, or use an encryption batch file to encrypt things in bulk. Anyway, there are plenty of ways — the key is your way of thinking.
ps: if it's encrypted like this, then no matter how much someone inserts echo into the batch file, it's useless, because first code has to be assigned the correct value before any encrypted command can run.

[ Last edited by zw19750516 on 2008-6-23 at 12:57 AM ]

The idea of using variables to replace commands is often seen in batch virus applications. What is used here is not a "password" but "ciphertext". The biggest drawback of ciphertext is that the longer the program, the easier the ciphertext is to crack, because some commands will appear repeatedly, and all appear at the beginning of lines.