Random domains from Chrome

[suqitian]

• These domains are often accompanied with "isatap.*" or "wapd.*".
• Source code at intranet_redirect_detector.cc. So the Length of SLD is 7-15.

  // Start three fetchers on random hostnames.
  for (size_t i = 0; i < 3; ++i) {
  std::string url_string("http://");
  // We generate a random hostname with between 7 and 15 characters.
  const int num_chars = base::RandInt(7, 15);
  for (int j = 0; j < num_chars; ++j)
    url_string += ('a' + base::RandInt(0, 'z' - 'a'));
  GURL random_url(url_string + '/');
  std::unique_ptr<net::URLFetcher> fetcher = net::URLFetcher::Create(
      random_url, net::URLFetcher::HEAD, this, traffic_annotation);
  // We don't want these fetches to affect existing state in the profile.
  fetcher->SetLoadFlags(net::LOAD_DISABLE_CACHE |
                        net::LOAD_DO_NOT_SAVE_COOKIES |
                        net::LOAD_DO_NOT_SEND_COOKIES |
                        net::LOAD_DO_NOT_SEND_AUTH_DATA);
  fetcher->SetRequestContext(g_browser_process->system_request_context());
  fetcher->Start();
  net::URLFetcher* fetcher_ptr = fetcher.get();
  fetchers_[fetcher_ptr] = std::move(fetcher);
  }

• Maybe generate three domains per hour. Copy "chrome://net-internals/#dns" into Chrome address bar, I saw something like this.

Hostname	Family	Addresses	Expires
gypqzwgfzykdv	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 15:09:50.104	[Expired]
ocypnqxhtcuy	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 15:09:50.106	[Expired]
ojiunnm	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 15:09:50.107	[Expired]
eupziohh	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 16:09:51.233	[Expired]
kbhwwbxhyxsvbb	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 16:09:51.233	[Expired]
vgfsnohsnqeyeg	IPV4	error: -105 (ERR_NAME_NOT_RESOLVED)	2017-05-03 16:09:51.234	[Expired]